tty: add parenthesis to macro POLL_PERIOD in rocket.c

Macros should be enclosed in parenthesis
Signed-off-by: Cong Ding <dinggnu@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/rocket.c

@@ -55,7 +55,7 @@
 #undef REV_PCI_ORDER
 #undef ROCKET_DEBUG_IO
 
-#define POLL_PERIOD HZ/100	/*  Polling period .01 seconds (10ms) */
+#define POLL_PERIOD (HZ/100)	/*  Polling period .01 seconds (10ms) */
 
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