Btrfs: Add sparse checking to Makefile

Signed-off-by: NChris Mason <chris.mason@oracle.com>

fs/btrfs/Makefile

@@ -3,8 +3,13 @@ CFLAGS = -g -Wall
 headers = radix-tree.h ctree.h disk-io.h kerncompat.h print-tree.h
 objects = ctree.o disk-io.o radix-tree.o mkfs.o extent-tree.o print-tree.o
 
-#.c.o:
-#	$(CC) $(CFLAGS) -c $<
+# if you don't have sparse installed, use ls instead
+check=sparse
+#check=ls
+
+.c.o:
+	$(check) $<
+	$(CC) $(CFLAGS) -c $<
 
 all: tester debug-tree
 

fs/btrfs/debug-tree.c

@@ -6,7 +6,7 @@
 #include "disk-io.h"
 #include "print-tree.h"
 
-int main() {
+int main(int ac, char **av) {
 	struct ctree_super_block super;
 	struct ctree_root *root;
 	radix_tree_init();