py: Fix mp_printf integer size mismatches.

The type of the argument must match the format string.  Add casts to ensure
that they do.

It's possible that casting from `size_t` to `unsigned` loses the correct
values by masking off upper bits, but it seems likely that the quantities
involved in practice are small enough that the `%u` formatter (32 bits on
most platforms, 16 on pic16bit) will in fact hold the correct value.

The alternative, casting to a wider type, adds code size.

These locations were found using an experimental gcc plugin for `mp_printf`
error checking, cross-building for x64 windows on Linux.

In one case there was already a cast, but it was written incorrectly and
did not have the intended effect.

Signed-off-by: Jeff Epler <jepler@gmail.com>

Author: jepler

py/gc.c

@@ -1202,7 +1202,7 @@ void gc_dump_alloc_table(const mp_print_t *print) {
                     }
                     if (bl2 - bl >= 2 * DUMP_BYTES_PER_LINE) {
                         // there are at least 2 lines containing only free blocks, so abbreviate their printing
-                        mp_printf(print, "\n       (%u lines all free)", (uint)(bl2 - bl) / DUMP_BYTES_PER_LINE);
+                        mp_printf(print, "\n       (%u lines all free)", (uint)((bl2 - bl) / DUMP_BYTES_PER_LINE));
                         bl = bl2 & (~(DUMP_BYTES_PER_LINE - 1));
                         if (bl >= area->gc_alloc_table_byte_len * BLOCKS_PER_ATB) {
                             // got to end of heap

py/modmicropython.c

@@ -98,7 +98,7 @@ static mp_obj_t mp_micropython_qstr_info(size_t n_args, const mp_obj_t *args) {
     size_t n_pool, n_qstr, n_str_data_bytes, n_total_bytes;
     qstr_pool_info(&n_pool, &n_qstr, &n_str_data_bytes, &n_total_bytes);
     mp_printf(&mp_plat_print, "qstr pool: n_pool=%u, n_qstr=%u, n_str_data_bytes=%u, n_total_bytes=%u\n",
-        n_pool, n_qstr, n_str_data_bytes, n_total_bytes);
+        (uint)n_pool, (uint)n_qstr, (uint)n_str_data_bytes, (uint)n_total_bytes);
     if (n_args == 1) {
         // arg given means dump qstr data
         qstr_dump_data();