ext4_utils: Fix non-linux builds

Change-Id: I5a22083645055abc36a3addc4eae45b40a7a6b2b
diff --git a/ext4_utils/wipe.c b/ext4_utils/wipe.c
index c7ba6db..990b82f 100644
--- a/ext4_utils/wipe.c
+++ b/ext4_utils/wipe.c
@@ -54,7 +54,7 @@
 	return 0;
 }
 #else
-int wipe_block_device(int fd)
+int wipe_block_device(int fd, int len)
 {
 	error("wipe not supported on non-linux platforms");
 	return 1;