multi: update linter, fix new issues

watchtower/wtdb/migration3/client_db_test.go

@@ -101,13 +101,9 @@ func TestMigrateChannelIDIndex(t *testing.T) {
 				// If the migration fails, the details bucket
 				// should be untouched.
 				if test.shouldFail {
-					if err := migtest.VerifyDB(
+					return migtest.VerifyDB(
 						tx, cChanDetailsBkt, test.pre,
-					); err != nil {
-						return err
-					}
-
-					return nil
+					)
 				}
 
 				// Else, we expect an updated summary bucket