net: mctp: Fix bad kfree_skb in bind lookup test

The kunit test's skb_pkt is consumed by mctp_dst_input() so shouldn't be
freed separately.

Fixes: e6d8e7d ("net: mctp: Add bind lookup test")
Reported-by: Alexandre Ghiti <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Matt Johnston <[email protected]>
Tested-by: Alexandre Ghiti <[email protected]>
Link: https://patch.msgid.link/20250812-fix-mctp-bind-test-v1-1-5e2128664eb3@codeconstruct.com.au
Signed-off-by: Jakub Kicinski <[email protected]>

Author: mkj

net/mctp/test/route-test.c

@@ -1586,7 +1586,6 @@ static void mctp_test_bind_lookup(struct kunit *test)
 
 cleanup:
 	kfree_skb(skb_sock);
-	kfree_skb(skb_pkt);
 
 	/* Drop all binds */
 	for (size_t i = 0; i < ARRAY_SIZE(lookup_binds); i++)