[SERIAL] Remove unused variable in sa1100.c

Since the spinlock was removed from sa1100_start_tx(), the "flags"
variable becomes redundant.  Remove it.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/serial/sa1100.c b/drivers/serial/sa1100.c
index 0e3daf6..25a0864 100644
--- a/drivers/serial/sa1100.c
+++ b/drivers/serial/sa1100.c
@@ -161,7 +161,6 @@
 static void sa1100_start_tx(struct uart_port *port)
 {
 	struct sa1100_port *sport = (struct sa1100_port *)port;
-	unsigned long flags;
 	u32 utcr3;
 
 	utcr3 = UART_GET_UTCR3(sport);