NFSv4.1/flexfiles: Fix freeing of mirrors
NFSv4.1/flexfiles: Fix freeing of mirrors

Mirrors are now shared objects, so we should not be freeing them directly
inside ff_layout_free_lseg(). We should already be doing the right thing
in _ff_layout_free_lseg(), so just let it handle things.

Also ensure that ff_layout_free_mirror() frees the RPC credential if it
is set.

Fixes: 28a0d72c6867 ("Add refcounting to struct nfs4_ff_layout_mirror")
Signed-off-by: Trond Myklebust <cc958843532c615cbd4920e868f78c7985331a5a@primarydata.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs