libceph: make ceph_pr_addr take an struct ceph_entity_addr pointer

GCC9 is throwing a lot of warnings about unaligned accesses by
callers of ceph_pr_addr. All of the current callers are passing a
pointer to the sockaddr inside struct ceph_entity_addr.

Fix it to take a pointer to a struct ceph_entity_addr instead,
and then have the function make a copy of the sockaddr before
printing it.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>