Fix tautological conditions (#30735)

As discovered by https://github.com/go-gitea/gitea/pull/30729.

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Co-authored-by: Giteabot <teabot@gitea.io>

services/auth/source/oauth2/providers.go

@@ -182,7 +182,7 @@ func createProvider(providerName string, source *Source) (goth.Provider, error)
 	}
 
 	// always set the name if provider is created so we can support multiple setups of 1 provider
-	if err == nil && provider != nil {
+	if provider != nil {
 		provider.SetName(providerName)
 	}