NFSv4.1 adds additional flags to the share_access argument of the open
call.  These flags need to be masked out in some of the existing code,
but current code does that inconsistently.
Tested-by: NMichael Groshans <groshans@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>