ceph: Fix up after semantic merge conflict

The previous ceph-client merge resulted in ceph not even building,
because there was a merge conflict that wasn't visible as an actual data
conflict: commit 7221fe4c ("ceph: add acl for cephfs") added support
for POSIX ACL's into Ceph, but unluckily we also had the VFS tree change
a lot of the POSIX ACL helper functions to be much more helpful to
filesystems (see for example commits 2aeccbe9 "fs: add generic
xattr_acl handlers", 5bf3258f "fs: make posix_acl_chmod more useful"
and 37bc1539 "fs: make posix_acl_create more useful")

The reason this conflict wasn't obvious was many-fold: because it was a
semantic conflict rather than a data conflict, it wasn't visible in the
git merge as a conflict.  And because the VFS tree hadn't been in
linux-next, people hadn't become aware of it that way.  And because I
was at jury duty this morning, I was using my laptop and as a result not
doing constant "allmodconfig" builds.

Anyway, this fixes the build and ...