PFSELFTEST: less false positives.
PFSELFTEST: less false positives.

This is just a quickfix, for the nature of the test the right way to fix
it is to average the error of N runs, since otherwise it is always
possible to get a false positive with a bad run, or to minimize too much
this possibility we may end testing with too much "large" error ranges.

JackieXie168/redis,JackieXie168/redis,JackieXie168/redis,JackieXie168/redis