vmstat: Fixed initial si,so,bi,bo,in & cs values

In the default display option, the first line of stats output in the
above mentioned columns was incorrect.

Reference(s):
procps-ng/procps#15
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=668580

Signed off by: Sanskriti Sharma <sansharm@redhat.com>
1 job for vmstat-avg in 1 minute and 57 seconds
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Status Job ID Name Coverage
  Test
passed #88938594
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00:01:57