LU-812 compat: clean up mutex lock to use kernel mutex primitive

LU-812 compat: clean up mutex lock to use kernel mutex primitive

Linux has removed DECLARE_MUTEX and init_MUTEX/_LOCKED which
were defined with semaphore functions. Instead of continuing to
map the cfs_mutex_*() functions to semaphore, this patch
maps these functions to existing kernel mutex primitive.

Change-Id: Ie814dd2a04f506b67b20b474c4a04147413d6506
Signed-off-by: Wally Wang <wang@cray.com>
Reviewed-on: http://review.whamcloud.com/1949
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Lai Siyao <laisiyao@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>