typo fixes: occuring -> occurring

Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/drivers/serial/pxa.c b/drivers/serial/pxa.c
index 0fa0ccc..bf85b57 100644
--- a/drivers/serial/pxa.c
+++ b/drivers/serial/pxa.c
@@ -390,7 +390,7 @@
 
 	/*
 	 * Finally, enable interrupts.  Note: Modem status interrupts
-	 * are set via set_termios(), which will be occuring imminently
+	 * are set via set_termios(), which will be occurring imminently
 	 * anyway, so we don't enable them here.
 	 */
 	up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;