netfilter: nft_socket: fix module autoload

Add alias definition for module autoload when adding socket rules.

Fixes: 554ced0 ("netfilter: nf_tables: add support for native socket matching")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nft_socket.c

@@ -142,3 +142,4 @@ module_exit(nft_socket_module_exit);
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Máté Eckl");
 MODULE_DESCRIPTION("nf_tables socket match module");
+MODULE_ALIAS_NFT_EXPR("socket");