btrfs/ctree.c: remove the unnecessary 'return -1;' at the end of bin_search

The code path should not reach there. Remove it.
Signed-off-by: NWang Sheng-Hui <shhuiw@gmail.com>

fs/btrfs/ctree.c

@@ -854,20 +854,18 @@ static noinline int generic_bin_search(struct extent_buffer *eb,
 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
 		      int level, int *slot)
 {
-	if (level == 0) {
+	if (level == 0)
 		return generic_bin_search(eb,
 					  offsetof(struct btrfs_leaf, items),
 					  sizeof(struct btrfs_item),
 					  key, btrfs_header_nritems(eb),
 					  slot);
-	} else {
+	else
 		return generic_bin_search(eb,
 					  offsetof(struct btrfs_node, ptrs),
 					  sizeof(struct btrfs_key_ptr),
 					  key, btrfs_header_nritems(eb),
 					  slot);
-	}
-	return -1;
 }
 
 int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key,