shell: use min() macro

source/shell/flash.c

@@ -157,7 +157,7 @@ static void do_flash_write(const char *s)
 		return;
 
 	while (len) {
-		nbytes = (len > 256) ? 256 : len;
+		nbytes = min(len, 256);
 		parse_hex(stdin, buf, nbytes);
 		printf("\n");
 		print_hex_ascii(buf, nbytes);