security: dac: Add is_toplevel to SetImageLabelInternal

This will simplify future patches and make the logic easier to follow
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NCole Robinson <crobinso@redhat.com>

src/security/security_dac.c

@@ -884,6 +884,7 @@ virSecurityDACSetImageLabelInternal(virSecurityManagerPtr mgr,
     virSecurityDeviceLabelDefPtr parent_seclabel = NULL;
     virSecurityDACDataPtr priv = virSecurityManagerGetPrivateData(mgr);
     bool remember;
+    bool is_toplevel = parent == src;
     uid_t user;
     gid_t group;
 
@@ -928,7 +929,7 @@ virSecurityDACSetImageLabelInternal(virSecurityManagerPtr mgr,
      * but the top layer, or read only image, or disk explicitly
      * marked as shared.
      */
-    remember = src == parent && !src->readonly && !src->shared;
+    remember = is_toplevel && !src->readonly && !src->shared;
 
     return virSecurityDACSetOwnership(mgr, src, NULL, user, group, remember);
 }