xen/ns16550: address violations of MISRA C:2012 Rule 13.1

Rule 13.1: Initializer lists shall not contain persistent side effects

The assignment operation in:

.irq = rc = uart->irq,

is a persistent side effect in a struct initializer list.

This patch assigns rc separately outside the structure.

No functional change.

Signed-off-by: Simone Ballarin <simone.ballarin@bugseng.com>
Signed-off-by: Maria Celeste Cesario <maria.celeste.cesario@bugseng.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

xen/drivers/char/ns16550.c

@@ -441,10 +441,12 @@ static void __init cf_check ns16550_init_postirq(struct serial_port *port)
             struct msi_info msi = {
                 .sbdf = PCI_SBDF(0, uart->ps_bdf[0], uart->ps_bdf[1],
                                  uart->ps_bdf[2]),
-                .irq = rc = uart->irq,
+                .irq = uart->irq,
                 .entry_nr = 1
             };
 
+            rc = uart->irq;
+
             if ( rc > 0 )
             {
                 struct msi_desc *msi_desc = NULL;