LU-3963 libcfs: remove cfs_hash_long

LU-3963 libcfs: remove cfs_hash_long

Replace the name with Linux defined hash_long.
The similar patch has already been submitted upstream.

Signed-off-by: Peng Tao <bergwolf@gmail.com>
Change-Id: Ia96bb703284ed4843c4433a1a50539d9c68ed6d1
Reviewed-on: http://review.whamcloud.com/9268
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Liang Zhen <liang.zhen@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>