[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/lops.c b/fs/gfs2/lops.c
index efb1087..a065f76 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -79,7 +79,7 @@
 	gfs2_trans_add_gl(bd->bd_gl);
 
 	gfs2_meta_check(sdp, bd->bd_bh);
-	gfs2_meta_pin(sdp, bd->bd_bh);
+	gfs2_pin(sdp, bd->bd_bh);
 
 	gfs2_log_lock(sdp);
 	sdp->sd_log_num_buf++;
@@ -169,7 +169,7 @@
 		list_del_init(&bd->bd_le.le_list);
 		sdp->sd_log_num_buf--;
 
-		gfs2_meta_unpin(sdp, bd->bd_bh, ai);
+		gfs2_unpin(sdp, bd->bd_bh, ai);
 	}
 	gfs2_assert_warn(sdp, !sdp->sd_log_num_buf);
 }