LU-553 add checkpatch.pl for Lustre coding style

LU-553 add checkpatch.pl for Lustre coding style

Add a modified version of the Linux kernel checkpatch.pl script (from 2.6.38)
to Lustre for validating patches against the Lustre coding style. The Lustre
coding style is largely the same as the kernel, except using spaces instead of
tabs for indenting.

Change-Id: Ia278370e0867c03e5f0814ef16109f64bd2bb9b3
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-on: http://review.whamcloud.com/1167
Reviewed-by: Johann Lombardi <johann@whamcloud.com>
Tested-by: Johann Lombardi <johann@whamcloud.com>