net: Fix memory leak in the proto_register function

If the slub allocator is used, kmem_cache_create() may merge two or more
kmem_cache's into one but the cache name pointer is not updated and
kmem_cache_name() is no longer guaranteed to return the pointer passed
to the former function. This patch stores the kmalloc'ed pointers in the
corresponding request_sock_ops and timewait_sock_ops structures.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>