RM-790 : fix Kernel string mismatch for ppc64le in RPMs

RM-790 : fix Kernel string mismatch for ppc64le in RPMs

The macro in the kernel RPMs for ppc64 provided
by Redhat describing the kernel version supported,
mismatch the content of the macro of the Lustre kernel
client modules for ppc64le describing the required
kernel. This leads to unresolved dependency errors
during installation of the Lustre client modules
although the kernel versions match actually.

While Redhat uses the convention:

kernel = <major-number>-<minor-release-number>.el6

the following string is used in Lustre client RPM
for the required kernel version:

kernel = <major-number>-<minor-release-number>.el6.ppc64le

The patch will remove the trailing string '.ppc64le' in
macro 'krequires' defined in the lustre specfile
describing the software dependeny.

AUTOTEST:ONLY:sanity

[Shilong added autotest args]

Change-Id: Id1d9fd92928a567048d5ad6e9d0c872b5666b4e6
Signed-off-by: Gu Zheng <gzheng@ddn.com>
Signed-off-by: Wang Shilong <wshilong@ddn.com>
Reviewed-on: https://review.whamcloud.com/41877
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Andreas Dilger <adilger@whamcloud.com>