gfs2: Replace GIF_DEFER_DELETE with GLF_DEFER_DELETE

[ Upstream commit 3774f53d ]

Having this flag attached to the iopen glock instead of the inode is
much simpler; it eliminates a protential weird race in gfs2_try_evict().

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Stable-dep-of: 2c63986d ("gfs2: deallocate inodes in gfs2_create_inode")
Signed-off-by: Sasha Levin <sashal@kernel.org>