do not return an error in AbortMultipartUpload() (#18135)

returning an error is a bit undefined in AWS S3
as it may return an error or not depending on the
time from AbortMultipartUpload().

cmd/object-multipart-handlers.go

@@ -1075,8 +1075,13 @@ func (api objectAPIHandlers) AbortMultipartUploadHandler(w http.ResponseWriter,
 	}
 	opts := ObjectOptions{}
 	if err := abortMultipartUpload(ctx, bucket, object, uploadID, opts); err != nil {
-		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
-		return
+		switch err.(type) {
+		case InvalidUploadID:
+			// Do not have return an error for non-existent upload-id
+		default:
+			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
+			return
+		}
 	}
 
 	writeSuccessNoContent(w)