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: I2d116c6769f9211825dc8ddaead05914f2116c60
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-on: http://review.whamcloud.com/1164
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>