tty: serial: linflexuart: Use DEFINE_SPINLOCK() for spinlock

spinlock can be initialized automatically with DEFINE_SPINLOCK()
rather than explicitly calling spin_lock_init().
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20190827114614.102037-1-weiyongjun1@huawei.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/fsl_linflexuart.c

@@ -136,7 +136,7 @@ MODULE_DEVICE_TABLE(of, linflex_dt_ids);
 #ifdef CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE
 static struct uart_port *earlycon_port;
 static bool linflex_earlycon_same_instance;
-static spinlock_t init_lock;
+static DEFINE_SPINLOCK(init_lock);
 static bool during_init;
 
 static struct {
@@ -922,10 +922,6 @@ static int __init linflex_serial_init(void)
 	if (ret)
 		uart_unregister_driver(&linflex_reg);
 
-#ifdef CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE
-	spin_lock_init(&init_lock);
-#endif
-
 	return ret;
 }