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

fs/Vfat.cpp

@@ -114,7 +114,7 @@ status_t Check(const std::string& source) {
                 errno = EIO;
                 return -1;
         }
-    } while (0);
+    } while (1);
 
     return 0;
 }