exfat: release 6.0.0 version

This version number is sync with linux mainline.
Major changes are:
 - Use updated exfat_chain directly instead of snapshot values  in rename.
 - fix the error code of rename syscall.
 - cleanup and suppress the superfluous error messages.
 - remove duplicate directory entry update.
 - fix integer overflow on large partition.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>