[PATCH] improve precision of process accounting.
The unit of the cputime accouting values that are stored per process is currently a microsecond. The CPU timer has a maximum granularity of 2**-12 microseconds. There is no benefit in storing the per process values in the lesser precision and there is the disadvantage that the backend has to do the rounding to microseconds. The better solution is to use the maximum granularity of the CPU timer as cputime unit. Signed-off-by: Martin Schwidefsky <firstname.lastname@example.org>