[PATCH 5 of 6] Fixed unused variable in ngx_set_srcaddr_cmsg() on MINIX

[Maxim Dounin]

# HG changeset patch
# User Maxim Dounin <mdounin at mdounin.ru>
# Date 1748209507 -10800
#      Mon May 26 00:45:07 2025 +0300
# Node ID 7a595fa6ade10f801f6e9bc84a7fd8fc1f9cca21
# Parent  3e11162ed39312387fc79a731071b0a50aa15acc
Fixed unused variable in ngx_set_srcaddr_cmsg() on MINIX.

diff --git a/src/os/unix/ngx_udp_sendmsg_chain.c b/src/os/unix/ngx_udp_sendmsg_chain.c
--- a/src/os/unix/ngx_udp_sendmsg_chain.c
+++ b/src/os/unix/ngx_udp_sendmsg_chain.c
@@ -245,7 +245,10 @@ ngx_sendmsg_vec(ngx_connection_t *c, ngx
 size_t
 ngx_set_srcaddr_cmsg(struct cmsghdr *cmsg, struct sockaddr *local_sockaddr)
 {
+#if (NGX_HAVE_IP_SENDSRCADDR || NGX_HAVE_IP_PKTINFO                           \
+     || (NGX_HAVE_INET6 && NGX_HAVE_IPV6_RECVPKTINFO))
     size_t                len;
+#endif
 #if (NGX_HAVE_IP_SENDSRCADDR)
     struct in_addr       *addr;
     struct sockaddr_in   *sin;