Enable the errorAssertions govet check for mattermost-server code (#17346)

* Enable the errorAssertions govet check for mattermost-server code

* Removing unnecesary change

* Fixing some tests

* Fixing tests

* Fixing more after merge

* Fixing new offending entries

* Fixing small vet checks

* Fixing new cases detected by govet

* Fixing remote_cluster_test errors

* Fixing assertion

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

api4/file_test.go

@@ -1085,37 +1085,37 @@ func TestSearchFiles(t *testing.T) {
 	Client := th.Client
 
 	filename := "search for fileInfo1"
-	fileInfo1, err := th.App.UploadFile(data, th.BasicChannel.Id, filename)
-	require.Nil(t, err)
+	fileInfo1, appErr := th.App.UploadFile(data, th.BasicChannel.Id, filename)
+	require.Nil(t, appErr)
 	err = th.App.Srv().Store.FileInfo().AttachToPost(fileInfo1.Id, th.BasicPost.Id, th.BasicUser.Id)
-	require.Nil(t, err)
+	require.NoError(t, err)
 
 	filename = "search for fileInfo2"
-	fileInfo2, err := th.App.UploadFile(data, th.BasicChannel.Id, filename)
-	require.Nil(t, err)
+	fileInfo2, appErr := th.App.UploadFile(data, th.BasicChannel.Id, filename)
+	require.Nil(t, appErr)
 	err = th.App.Srv().Store.FileInfo().AttachToPost(fileInfo2.Id, th.BasicPost.Id, th.BasicUser.Id)
-	require.Nil(t, err)
+	require.NoError(t, err)
 
 	filename = "tagged search for fileInfo3"
-	fileInfo3, err := th.App.UploadFile(data, th.BasicChannel.Id, filename)
-	require.Nil(t, err)
+	fileInfo3, appErr := th.App.UploadFile(data, th.BasicChannel.Id, filename)
+	require.Nil(t, appErr)
 	err = th.App.Srv().Store.FileInfo().AttachToPost(fileInfo3.Id, th.BasicPost.Id, th.BasicUser.Id)
-	require.Nil(t, err)
+	require.NoError(t, err)
 
 	filename = "tagged for fileInfo4"
-	fileInfo4, err := th.App.UploadFile(data, th.BasicChannel.Id, filename)
-	require.Nil(t, err)
+	fileInfo4, appErr := th.App.UploadFile(data, th.BasicChannel.Id, filename)
+	require.Nil(t, appErr)
 	err = th.App.Srv().Store.FileInfo().AttachToPost(fileInfo4.Id, th.BasicPost.Id, th.BasicUser.Id)
-	require.Nil(t, err)
+	require.NoError(t, err)
 
 	archivedChannel := th.CreatePublicChannel()
-	fileInfo5, err := th.App.UploadFile(data, archivedChannel.Id, "tagged for fileInfo3")
-	require.Nil(t, err)
+	fileInfo5, appErr := th.App.UploadFile(data, archivedChannel.Id, "tagged for fileInfo3")
+	require.Nil(t, appErr)
 	post := &model.Post{ChannelId: archivedChannel.Id, Message: model.NewId() + "a"}
 	rpost, resp := Client.CreatePost(post)
 	CheckNoError(t, resp)
 	err = th.App.Srv().Store.FileInfo().AttachToPost(fileInfo5.Id, rpost.Id, th.BasicUser.Id)
-	require.Nil(t, err)
+	require.NoError(t, err)
 	th.Client.DeleteChannel(archivedChannel.Id)
 
 	terms := "search"