Fix crash in DAC driver with no seclabels

With dynamic_ownership = 1 but no seclabels, RestoreChardevLabel
dereferences the NULL seclabel when checking if norelabel is set.

Remove this check, since it is already done in RestoreSecurityAllLabel
and if norelabel is set, RestoreChardevLabel is never called.

src/security/security_dac.c

@@ -768,22 +768,19 @@ virSecurityDACSetChardevLabel(virSecurityManagerPtr mgr,
 
 static int
 virSecurityDACRestoreChardevLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED,
-                                  virDomainDefPtr def,
+                                  virDomainDefPtr def ATTRIBUTE_UNUSED,
                                   virDomainChrDefPtr dev,
                                   virDomainChrSourceDefPtr dev_source)
 {
-    virSecurityLabelDefPtr seclabel;
     virSecurityDeviceLabelDefPtr chr_seclabel = NULL;
     char *in = NULL, *out = NULL;
     int ret = -1;
 
-    seclabel = virDomainDefGetSecurityLabelDef(def, SECURITY_DAC_NAME);
-
     if (dev)
         chr_seclabel = virDomainChrDefGetSecurityLabelDef(dev,
                                                           SECURITY_DAC_NAME);
 
-    if (seclabel->norelabel || (chr_seclabel && chr_seclabel->norelabel))
+    if (chr_seclabel && chr_seclabel->norelabel)
         return 0;
 
     switch ((enum virDomainChrType) dev_source->type) {