ns16550: remove partial explicit initializer

The initializer of 'ns16550_com' violates MISRA C Rule 9.3
because it explicitly initializes only the first element of the array,
but the semantics is the same if the explicit initialization is
omitted.

No functional change.

Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

xen/drivers/char/ns16550.c

@@ -73,7 +73,7 @@ static struct ns16550 {
     bool msi;
     const struct ns16550_config_param *param; /* Points into .init.*! */
 #endif
-} ns16550_com[2] = { { 0 } };
+} ns16550_com[2] = {};
 
 #ifdef NS16550_PCI
 struct ns16550_config {