library: eliminate redundant assignment, <meminfo> api

library: eliminate redundant assignment, <meminfo> api

With the memset to zero of a 'new' meminfo_data struct
near the beginning of the meminfo_read_failed function
there's never a need to later set anything in it to 0.

[ who knows, our patch might even coax opensuse into ]
[ reevaluating that 4.0.0 'overflow' guy named below ]

Reference(s):
. overflow: 'procps-ng-4.0.0-integer-overflow.patch'

Signed-off-by: Jim Warner <james.warner@comcast.net>