xen: fix logic bug

The recent switch to enable -Wlogical-op paid off again.
gcc 4.5.0 (rawhide) is smarter than 4.4.4 (Fedora 13).

* src/xen/xend_internal.c (xenDaemonAttachDeviceFlags)
(xenDaemonUpdateDeviceFlags, xenDaemonDetachDeviceFlags): Use
correct operator.
Signed-off-by: NEric Blake <eblake@redhat.com>

src/xen/xend_internal.c

@@ -3888,7 +3888,7 @@ xenDaemonAttachDeviceFlags(virDomainPtr domain, const char *xml,
     } else {
         /* Only live config can be changed if xendConfigVersion < 3 */
         if (priv->xendConfigVersion < 3 &&
-            (flags != VIR_DOMAIN_DEVICE_MODIFY_CURRENT ||
+            (flags != VIR_DOMAIN_DEVICE_MODIFY_CURRENT &&
              flags != VIR_DOMAIN_DEVICE_MODIFY_LIVE)) {
             virXendError(VIR_ERR_OPERATION_INVALID, "%s",
                          _("Xend version does not support modifying "
@@ -4027,7 +4027,7 @@ xenDaemonUpdateDeviceFlags(virDomainPtr domain, const char *xml,
     } else {
         /* Only live config can be changed if xendConfigVersion < 3 */
         if (priv->xendConfigVersion < 3 &&
-            (flags != VIR_DOMAIN_DEVICE_MODIFY_CURRENT ||
+            (flags != VIR_DOMAIN_DEVICE_MODIFY_CURRENT &&
              flags != VIR_DOMAIN_DEVICE_MODIFY_LIVE)) {
             virXendError(VIR_ERR_OPERATION_INVALID, "%s",
                          _("Xend version does not support modifying "
@@ -4138,7 +4138,7 @@ xenDaemonDetachDeviceFlags(virDomainPtr domain, const char *xml,
     } else {
         /* Only live config can be changed if xendConfigVersion < 3 */
         if (priv->xendConfigVersion < 3 &&
-            (flags != VIR_DOMAIN_DEVICE_MODIFY_CURRENT ||
+            (flags != VIR_DOMAIN_DEVICE_MODIFY_CURRENT &&
              flags != VIR_DOMAIN_DEVICE_MODIFY_LIVE)) {
             virXendError(VIR_ERR_OPERATION_INVALID, "%s",
                          _("Xend version does not support modifying "