[PFKEY]: Sending an SADB_GET responds with an SADB_GET

[ Upstream commit: 435000be ]

Kernel needs to respond to an SADB_GET with the same message type to
conform to the RFC 2367 Section 3.1.5
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>