inet: use #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING consistently

Since commit 4e1beecc ("net/sock: Add kernel config
SOCK_RX_QUEUE_MAPPING"),
sk_rx_queue_mapping access is guarded by CONFIG_SOCK_RX_QUEUE_MAPPING.

Fixes: 54b92e84

 ("tcp: Migrate TCP_ESTABLISHED/TCP_SYN_RECV sockets in accept queues.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Tariq Toukan <tariqt@nvidia.com>
Acked-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>