net: move tap_set_sndbuf() to tap-linux.c

TUNSETSNDBUF is only available on linux

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

net/tap-solaris.c

@@ -183,3 +183,8 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required
     fcntl(fd, F_SETFL, O_NONBLOCK);
     return fd;
 }
+
+int tap_set_sndbuf(int fd, QemuOpts *opts)
+{
+    return 0;
+}