testing/cachetest: fix compilation error for arm64

fix compilation error:

cachetest_main.c:37:26: error: format '%u' expects argument of type 'unsigned int', but argument 5 has type 'size_t' {aka 'long unsigned int'} [-Werror=format=]
   37 | #define CACHETEST_PREFIX "CACHE Test: "
      |                          ^~~~~~~~~~~~~~
cachetest_main.c:150:20: note: in expansion of macro 'CACHETEST_PREFIX'
  150 |   syslog(LOG_INFO, CACHETEST_PREFIX "waddr:%p, uncacheble addr start:%p,"
      |                    ^~~~~~~~~~~~~~~~
cachetest_main.c:151:17: note: format string is defined here
  151 |          "size:%u\n", info->waddr,
      |                ~^
      |                 |
      |                 unsigned int
      |                %lu

Signed-off-by: raiden00pl <[email protected]>

Author: raiden00pl

testing/mm/cachetest/cachetest_main.c

@@ -148,7 +148,7 @@ static void cachetest_parse_commandline(int argc, FAR char **argv,
     }
 
   syslog(LOG_INFO, CACHETEST_PREFIX "waddr:%p, uncacheble addr start:%p,"
-         "size:%u\n", info->waddr,
+         "size:%zu\n", info->waddr,
          (FAR char *)((uintptr_t)info->waddr | info->offset), info->size);
 }