pgstat_read_statsfiles() and reset timestamp

Hi,

pgstat_read_statsfiles() sets each stat_reset_timestamp to
the current timestamp, at the beginning of the function,
just in case we fail to load the existing statsfile. This code is
originally introduced by commit 4c468b37a2.

But commit ad1b5c842b changed pgstat_read_statsfiles() so that
the stats including stat_reset_timestamp are zeroed in that case,
so now there seems no need to set each stat_reset_timestamp.
Thought?

Attached is the patch that removes such unnecessary sets of
stat_reset_timestamp from pgstat_read_statsfiles().

Regards,

-- 
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION