tty: xtensa/iss: Use min() to fix Coccinelle warning

Inline strlen() and use min() to fix the following Coccinelle/coccicheck
warning reported by minmax.cocci:

	WARNING opportunity for min()
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Message-Id: <20240404075811.6936-3-thorsten.blum@toblux.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/platforms/iss/console.c

@@ -166,10 +166,8 @@ late_initcall(rs_init);
 
 static void iss_console_write(struct console *co, const char *s, unsigned count)
 {
-	if (s && *s != 0) {
-		int len = strlen(s);
-		simc_write(1, s, count < len ? count : len);
-	}
+	if (s && *s != 0)
+		simc_write(1, s, min(count, strlen(s)));
 }
 
 static struct tty_driver* iss_console_device(struct console *c, int *index)