Btrfs: parse parent 0 into correct value in tracepoint

Value 0 is not a tree id, so besides an upper limit, a lower limit is
necessary as well while parsing root types of tracepoint.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index 54fab04..ea546a4 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -45,7 +45,8 @@
 
 #define show_root_type(obj)						\
 	obj, ((obj >= BTRFS_DATA_RELOC_TREE_OBJECTID) ||		\
-	      (obj <= BTRFS_CSUM_TREE_OBJECTID )) ? __show_root_type(obj) : "-"
+	      (obj >= BTRFS_ROOT_TREE_OBJECTID &&			\
+	       obj <= BTRFS_CSUM_TREE_OBJECTID)) ? __show_root_type(obj) : "-"
 
 #define BTRFS_GROUP_FLAGS	\
 	{ BTRFS_BLOCK_GROUP_DATA,	"DATA"}, \