FileStore: remove dead code

This case wasn't reachable when it was introduced, and it's still not.

Signed-off-by: Greg Farnum <greg@inktank.com>
FileStore: do not use user_only in collection_getattrs

There's no particular reason why any of the callers of collection_getattrs
want to avoid looking at Ceph's internal xattrs.
It looks like this flag (set in 1862ddd88548fd4609f4fa9715dbad42a84d3775) was
set this way by mistake.
And finally, we don't actually set xattrs on collections anymore, anyway.

Signed-off-by: Greg Farnum <greg@inktank.com>
FileStore: remove user_only options from getattrs through the ObjectStore stack

This sort of awareness belongs at a higher level in the stack -- as
evidenced by nobody using the option at this level. Remove it from the
implementations and the interface

Signed-off-by: Greg Farnum <greg@inktank.com>
FileStore: remove the user_only param from _fgetattrs

Nobody sets it to true, so remove it!

Signed-off-by: Greg Farnum <greg@inktank.com>