Fix vfat retry fsck logic

On case 4 (filesystem modified), we attempt to recheck the filesystem,
but due to the while(0), this immediately returns 0, resulting in
mounting a filesystem with unfixed errors. This corrects that.

Bug: 340128961
Test: Ensure case 4 leads to retries
Change-Id: Ida2840538ad88c8de5341b0d71d3712d93b0cab1
1 file changed