kern/43616: msdosfs rename dir dir/.. fails with EROFS instead of expected EINVAL

[pooka%iki.fi@localhost]

>Number:         43616
>Category:       kern
>Synopsis:       msdosfs rename dir dir/.. fails with EROFS instead of expected 
>EINVAL
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Jul 14 17:25:00 +0000 2010
>Originator:     Antti Kantee
>Release:        
>Organization:
>Environment:
>Description:
summary says it all.  will commit test soon.
>How-To-Repeat:

>Fix: