Btrfs: Fixup last found extent caching

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index d92d08d..ae7f4c0 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -1,6 +1,6 @@
 
 CC=gcc
-CFLAGS = -Wall
+CFLAGS = -g -Wall
 headers = radix-tree.h ctree.h disk-io.h kerncompat.h print-tree.h list.h
 objects = ctree.o disk-io.o radix-tree.o mkfs.o extent-tree.o print-tree.o