mpy-cross/main: Fix return type of mp_import_stat.

Fixes issue #10951.

Signed-off-by: Damien George <damien@micropython.org>

mpy-cross/main.c

@@ -344,7 +344,7 @@ int main(int argc, char **argv) {
     return main_(argc, argv);
 }
 
-uint mp_import_stat(const char *path) {
+mp_import_stat_t mp_import_stat(const char *path) {
     (void)path;
     return MP_IMPORT_STAT_NO_EXIST;
 }