Ignore cast alignment warnings in inotify code for Xen.

The inotify Xen code causes a cast alignment warning, but this
is harmless since the kernel inotify interface will ensure
sufficient alignment of the inotify structs in the buffer being
read
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

src/xen/xen_inotify.c

@@ -278,7 +278,10 @@ reread:
         if (got < sizeof(struct inotify_event))
             goto cleanup; /* bad */
 
+        VIR_WARNINGS_NO_CAST_ALIGN
         e = (struct inotify_event *)tmp;
+        VIR_WARNINGS_RESET
+
         tmp += sizeof(struct inotify_event);
         got -= sizeof(struct inotify_event);