[MM-29111] Fix errcheck issues in server/channels/app/upload.go (#30678)

Co-authored-by: Claude <noreply@anthropic.com>

server/.golangci.yml

@@ -97,7 +97,6 @@ issues:
         channels/app/platform/license.go|\
         channels/app/slashcommands/command_test.go|\
         channels/app/slashcommands/helper_test.go|\
-        channels/app/upload.go|\
         channels/store/localcachelayer/channel_layer.go|\
         channels/store/localcachelayer/channel_layer_test.go|\
         channels/store/localcachelayer/emoji_layer.go|\

server/channels/app/upload.go

@@ -230,7 +230,16 @@ func (a *App) UploadData(c request.CTX, us *model.UploadSession, rd io.Reader) (
 			return nil, err
 		}
 		if written < minFirstPartSize && written != us.FileSize {
-			a.RemoveFile(uploadPath)
+			if fileErr := a.RemoveFile(uploadPath); fileErr != nil {
+				c.Logger().Warn("Failed to remove initial upload chunk that was too small",
+					mlog.Err(fileErr),
+					mlog.String("upload_path", uploadPath),
+					mlog.String("upload_id", us.Id),
+					mlog.String("filename", us.Filename),
+					mlog.Int("chunk_size", int(written)),
+					mlog.Int("min_size", minFirstPartSize),
+				)
+			}
 			var errStr string
 			if err != nil {
 				errStr = err.Error()