GFS2: cleanup file_operations mess

Remove the weird pointer to file_operations mess and replace it with
straight-forward defining of the lockinginstance names to the _nolock
variants.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --cc fs/gfs2/inode.c
Simple merge

diff --cc fs/gfs2/inode.h
Simple merge

diff --cc fs/gfs2/ops_file.c
Simple merge