dm: core: fix no null pointer detection in ofnode_get_addr_size_index()

Fixed a defect of a null pointer being discovered by Coverity Scan:
   CID 331544:  Null pointer dereferences  (REVERSE_INULL)
   Null-checking "size" suggests that it may be null, but it has already been
   dereferenced on all paths leading to the check.

Signed-off-by: Chen Guanqiao <chenguanqiao@kuaishou.com>
40 jobs for dm-pull-21jul21 in 57 minutes and 4 seconds (queued for 15 minutes and 12 seconds)
latest
Status Name Job ID Coverage
  Testsuites
passed Build envtools #296113

00:00:17

passed Build tools-only #296112

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passed Check for configs without MAINTAINERS entry #296111

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passed cppcheck #296107

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passed grep TODO/FIXME/HACK #296108

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passed htmldocs #296109

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passed Run binman, buildman, dtoc, Kconfig and patman testsuites #296114

00:00:54

passed Run tests for Nokia RX-51 (aka N900) #296115

00:02:51

passed sloccount #296110

00:00:29

 
  Test.Py
passed evb-ast2500 test.py #296120

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passed integratorcp_cm926ejs test.py #296122

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passed qemu_arm64 test.py #296124

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passed qemu_arm test.py #296123

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passed qemu_malta64el test.py #296128

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passed qemu_malta64 test.py #296127

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passed qemu_maltael test.py #296126

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passed qemu_malta test.py #296125

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passed qemu-ppce500 test.py #296129

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passed qemu-riscv32_spl test.py #296132

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passed qemu-riscv32 test.py #296130

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passed qemu-riscv64_spl test.py #296133

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passed qemu-riscv64 test.py #296131

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passed qemu-x86_64 test.py #296135

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passed qemu-x86 test.py #296134

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passed r2dplus_i82557c test.py #296136

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passed r2dplus_pcnet test.py #296137

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passed r2dplus_rtl8139 test.py #296138

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passed r2dplus_tulip test.py #296139

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passed sandbox_flattree test.py #296121

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passed sandbox_noinst_test.py #296119

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passed sandbox_spl test.py #296118

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passed sandbox test.py #296116

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passed sandbox with clang test.py #296117

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passed xilinx_versal_virt test.py #296141

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passed xilinx_zynq_virt test.py #296140

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passed xtfpga test.py #296142

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  World Build
passed build all 32bit ARM platforms #296143

00:36:39

passed build all 64bit ARM platforms #296144

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passed build all other platforms #296146

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passed build all PowerPC platforms #296145

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