kv: remove some tautological conditionals

Epic: none
Release note: None

Author: stevendanna

pkg/kv/client_test.go

@@ -874,10 +874,8 @@ func TestTxn_ReverseScan(t *testing.T) {
 			t.Errorf("expected empty, got %v", rows)
 		}
 		return err
-	}); err != nil {
-		if err == nil {
-			t.Errorf("expected a truncation error, got %s", err)
-		}
+	}); err == nil || !strings.Contains(err.Error(), "must be greater than start") {
+		t.Errorf("expected a truncation error, got %s", err)
 	}
 
 	// Try reverse scan with non-existent key.

pkg/kv/txn_test.go

@@ -119,9 +119,7 @@ func newTestTxnFactory(
 			}
 			if ba.Txn != nil && br.Txn == nil {
 				br.Txn = ba.Txn.Clone()
-				if pErr == nil {
-					br.Txn.Status = status
-				}
+				br.Txn.Status = status
 				// Update the MockTxnSender's proto.
 				*txn = *br.Txn
 			}