GFS2: Fix up "off by one" in the previous patch

The trace point should take extlen and not *ndata as the
extent length.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index b8935af..f1d1960 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -1378,7 +1378,7 @@
 				  ip->i_inode.i_gid);
 
 	rgd->rd_free_clone -= extlen;
-	trace_gfs2_block_alloc(ip, block, *ndata,
+	trace_gfs2_block_alloc(ip, block, extlen,
 			       dinode ? GFS2_BLKST_DINODE : GFS2_BLKST_USED);
 	*bn = block;
 	return 0;