locks: pass the cmd value to fcntl_getlk/getlk64

Once we introduce file private locks, we'll need to know what cmd value
was used, as that affects the ownership and whether a conflict would
arise.

Signed-off-by: Jeff Layton <jlayton@redhat.com>

diff --cc fs/fcntl.c
Simple merge

diff --cc fs/locks.c
Simple merge

diff --cc include/linux/fs.h
Simple merge