LU-284 strip .$arch off of kern vers for requires

LU-284 strip .$arch off of kern vers for requires

RHEL6 appends .arch to the end of the version in the utsrelease.h file.
The kernel RPM however provides that value with the .arch stripped off,
so do the same stripping in the lustre-modules RPM for it's Requires:.

Signed-off-by: Brian J. Murrell <brian@whamcloud.com>
Change-Id: Ib6ff32c006f184edceb5d667b649bb106d503faf
Reviewed-on: http://review.whamcloud.com/502
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: Hudson
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>