MinGW: Replace setsockopt by qemu_setsocketopt

Instead of adding missing type casts which are needed by MinGW for the
4th argument, the patch uses qemu_setsockopt which was invented for this
purpose.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/slirp/tcp_subr.c b/slirp/tcp_subr.c
index 7b7ad60..84a6bb5 100644
--- a/slirp/tcp_subr.c
+++ b/slirp/tcp_subr.c
@@ -338,9 +338,9 @@
 
     socket_set_nonblock(s);
     opt = 1;
-    setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(opt ));
+    qemu_setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
     opt = 1;
-    setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(opt ));
+    qemu_setsockopt(s, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt));
 
     addr.sin_family = AF_INET;
     if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) ==
@@ -427,9 +427,9 @@
     }
     socket_set_nonblock(s);
     opt = 1;
-    setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char *)&opt, sizeof(int));
+    qemu_setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(int));
     opt = 1;
-    setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (char *)&opt, sizeof(int));
+    qemu_setsockopt(s, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(int));
     socket_set_nodelay(s);
 
     so->so_fport = addr.sin_port;