[Bug Report] The upload component uploads files using the manual submit method, which will also upload files that do not meet the restriction specifications to the server

### Element UI version
2.15.7

### OS/Browsers version
chrome@98.0.4758.80

### Vue version
2.6.11

### Reproduction Link
https://codepen.io/mixiuu/pen/XWzaYzo?editors=1111

### Steps to reproduce
First upload pictures that do not conform to the format requirements. When uploading pictures that conform to the picture format, the file list is empty after calling submit.

### What is Expected?
upload only pictures in the correct format

### What is actually happening?
upload empty filelists