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

watchtower/wtdb/migration4/client_db_test.go

@@ -281,13 +281,9 @@ func after(shouldFail bool, preMigDB,
 			// If the migration fails, the sessions bucket should be
 			// untouched.
 			if shouldFail {
-				if err := migtest.VerifyDB(
+				return migtest.VerifyDB(
 					tx, cSessionBkt, preMigDB,
-				); err != nil {
-					return err
-				}
-
-				return nil
+				)
 			}
 
 			return migtest.VerifyDB(tx, cSessionBkt, postMigDB)

watchtower/wtdb/migration7/client_db_test.go

@@ -144,14 +144,10 @@ func TestMigrateChannelToSessionIndex(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.preDetails,
-					); err != nil {
-						return err
-					}
-
-					return nil
+					)
 				}
 
 				// Else, we expect an updated details bucket