nwfilter: Clean up a couple nwfilter_driver error paths

No need to goto cleanup and check "if (obj)" if we know (obj) isn't there,
so just return immediately.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

src/nwfilter/nwfilter_driver.c

@@ -391,7 +391,7 @@ nwfilterLookupByUUID(virConnectPtr conn,
     nwfilterDriverUnlock();
 
     if (!obj)
-        goto cleanup;
+        return NULL;
     def = virNWFilterObjGetDef(obj);
 
     if (virNWFilterLookupByUUIDEnsureACL(conn, def) < 0)
@@ -400,7 +400,6 @@ nwfilterLookupByUUID(virConnectPtr conn,
     ret = virGetNWFilter(conn, def->name, def->uuid);
 
  cleanup:
-    if (obj)
     virNWFilterObjUnlock(obj);
     return ret;
 }
@@ -421,7 +420,7 @@ nwfilterLookupByName(virConnectPtr conn,
     if (!obj) {
         virReportError(VIR_ERR_NO_NWFILTER,
                        _("no nwfilter with matching name '%s'"), name);
-        goto cleanup;
+        return NULL;
     }
     def = virNWFilterObjGetDef(obj);
 
@@ -431,7 +430,6 @@ nwfilterLookupByName(virConnectPtr conn,
     ret = virGetNWFilter(conn, def->name, def->uuid);
 
  cleanup:
-    if (obj)
     virNWFilterObjUnlock(obj);
     return ret;
 }
@@ -594,7 +592,7 @@ nwfilterGetXMLDesc(virNWFilterPtr nwfilter,
     nwfilterDriverUnlock();
 
     if (!obj)
-        goto cleanup;
+        return NULL;
     def = virNWFilterObjGetDef(obj);
 
     if (virNWFilterGetXMLDescEnsureACL(nwfilter->conn, def) < 0)
@@ -603,7 +601,6 @@ nwfilterGetXMLDesc(virNWFilterPtr nwfilter,
     ret = virNWFilterDefFormat(def);
 
  cleanup:
-    if (obj)
     virNWFilterObjUnlock(obj);
     return ret;
 }