Code style: changed "sizeof foo" to "sizeof(foo)" (thanks @sezero!)

(cherry picked from commit c6443d86c9)

test/checkkeysthreads.c

@@ -157,7 +157,7 @@ PrintText(const char *eventtype, const char *text)
     expanded[0] = '\0';
     for (spot = text; *spot; ++spot) {
         size_t length = SDL_strlen(expanded);
-        (void)SDL_snprintf(expanded + length, sizeof expanded - length, "\\x%.2x", (unsigned char)*spot);
+        (void)SDL_snprintf(expanded + length, sizeof(expanded) - length, "\\x%.2x", (unsigned char)*spot);
     }
     SDL_Log("%s Text (%s): \"%s%s\"\n", eventtype, expanded, *text == '"' ? "\\" : "", text);
 }