xfrm: Fix memory leak of aead algorithm name

commit 1a6509d99122 ("[IPSEC]: Add support for combined mode algorithms")
introduced aead. The function attach_aead kmemdup()s the algorithm
name during xfrm_state_construct().
However this memory is never freed.
Implementation has since been slightly modified in
commit ee5c23176fcc ("xfrm: Clone states properly on migration")
without resolving this leak.
This patch adds a kfree() call for the aead algorithm name.

Fixes: 1a6509d99122 ("[IPSEC]: Add support for combined mode algorithms")
Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Acked-by: Rami Rosen <roszenrami@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 9895a8c..a30f898d 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -332,6 +332,7 @@
 {
 	tasklet_hrtimer_cancel(&x->mtimer);
 	del_timer_sync(&x->rtimer);
+	kfree(x->aead);
 	kfree(x->aalg);
 	kfree(x->ealg);
 	kfree(x->calg);