net/tls: Make function get_rec() static

Fixes the following sparse warning:

net/tls/tls_sw.c:655:16: warning:
 symbol 'get_rec' was not declared. Should it be static?

Fixes: a42055e ("net/tls: Add support for async encryption of records for performance")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tls/tls_sw.c

@@ -637,7 +637,7 @@ static int memcopy_from_iter(struct sock *sk, struct iov_iter *from,
 	return rc;
 }
 
-struct tls_rec *get_rec(struct sock *sk)
+static struct tls_rec *get_rec(struct sock *sk)
 {
 	struct tls_context *tls_ctx = tls_get_ctx(sk);
 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);