drivers/char: address violation of MISRA C Rule 20.7

MISRA C Rule 20.7 states: "Expressions resulting from the expansion
of macro parameters shall be enclosed in parentheses". Therefore, some
macro definitions should gain additional parentheses to ensure that all
current and future users will be safe with respect to expansions that
can possibly alter the semantics of the passed-in macro parameter.

No functional chage.

Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

xen/drivers/char/omap-uart.c

@@ -48,8 +48,9 @@
 /* System configuration register */
 #define UART_OMAP_SYSC_DEF_CONF   0x0d   /* autoidle mode, wakeup is enabled */
 
-#define omap_read(uart, off)       readl((uart)->regs + (off<<REG_SHIFT))
-#define omap_write(uart, off, val) writel((val), (uart)->regs + (off<<REG_SHIFT))
+#define omap_read(uart, off)       readl((uart)->regs + ((off) << REG_SHIFT))
+#define omap_write(uart, off, val) writel(val, \
+                                          (uart)->regs + ((off) << REG_SHIFT))
 
 static struct omap_uart {
     u32 baud, clock_hz, data_bits, parity, stop_bits, fifo_size;