[GFS2] Rename gfs2_meta_pin to gfs2_pin

Since we'll need to pin data if we are going to journal it, then
I'm renaming this function to make it less confusing. It might also
be worth moving it into lops.c since there are no users outside that
file.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/meta_io.h b/fs/gfs2/meta_io.h
index 10fbf82..887cac3 100644
--- a/fs/gfs2/meta_io.h
+++ b/fs/gfs2/meta_io.h
@@ -65,9 +65,9 @@
 int gfs2_meta_reread(struct gfs2_sbd *sdp, struct buffer_head *bh, int flags);
 
 void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh, int meta);
-void gfs2_meta_pin(struct gfs2_sbd *sdp, struct buffer_head *bh);
-void gfs2_meta_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
-		 struct gfs2_ail *ai);
+void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh);
+void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
+		struct gfs2_ail *ai);
 
 void gfs2_meta_wipe(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen);