trace2: fix condition for logging error in 'Errorf()'

Change the condition determining whether to log the error from 'if isLogged'
to 'if !isLogged', since we want to log the error if it has *not* already
been logged.

Signed-off-by: Victoria Dye <[email protected]>

Author: vdye

internal/log/trace2.go

@@ -308,7 +308,7 @@ func (t *Trace2) Errorf(ctx context.Context, format string, a ...any) error {
 
 	err := loggedError(fmt.Errorf(format, a...))
 
-	if isLogged {
+	if !isLogged {
 		_, sharedFields := t.sharedFields(ctx)
 		t.logger.Info("error", sharedFields.with(
 			zap.String("msg", err.Error()),