GFS2: Stop looking for free blocks at end of rgrp

This patch adds a return code check after calling function
gfs2_rbm_from_block while determining the free extent size.
That way, when the end of an rgrp is reached, it won't try
to process unaligned blocks after the end.

Signed-off-by: Bob Peterson <[email protected]>
Signed-off-by: Steven Whitehouse <[email protected]>
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 738b388..712dd4f 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -350,10 +350,14 @@
 		BUG_ON(len < chunk_size);
 		len -= chunk_size;
 		block = gfs2_rbm_to_block(&rbm);
-		gfs2_rbm_from_block(&rbm, block + chunk_size);
-		n_unaligned = 3;
-		if (ptr)
+		if (gfs2_rbm_from_block(&rbm, block + chunk_size)) {
+			n_unaligned = 0;
 			break;
+		}
+		if (ptr) {
+			n_unaligned = 3;
+			break;
+		}
 		n_unaligned = len & 3;
 	}