ext4: fix format flag in ext4_ext_binsearch_idx()

fix ext_debug format flag in ext4_ext_binsearch_idx().

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 6f3b49b..496151f 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -603,7 +603,7 @@
 	}
 
 	path->p_idx = l - 1;
-	ext_debug("  -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block),
+	ext_debug("  -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
 		  ext4_idx_pblock(path->p_idx));
 
 #ifdef CHECK_BINSEARCH