Fix bug in dirup function

src/cpath/cpath.c

@@ -40,7 +40,7 @@ void dirup(char *dst, u64 levels, const char *path) {
     --length;
   }
 
-  for (u64 i = length - 1; i >= 0; --i) {
+  for (i64 i = length - 1; i >= 0; --i) {
     if (path[i] == path_sep) {
       ++sep_count;
       end_index = i;