ceph: initialize pathlen variable in reconnect_caps_cb

ceph: initialize pathlen variable in reconnect_caps_cb

[ Upstream commit ee2a095d3b24f300a5e11944d208801e928f108c ]

The smatch static checker warned about an uninitialized symbol usage in
this function, in the case where ceph_mdsc_build_path returns an error.

It turns out that that case is harmless, but it just looks sketchy.
Initialize the variable at declaration time, and remove the unneeded
setting of it later.

Fixes: a33f6432b3a6 ("ceph: encode inodes' parent/d_name in cap reconnect message")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>