vhost: do not generate signal when sendmsg fails

More precisely, do not generate a SIGPIPE signal if the peer
has closed the connection. Otherwise, it will terminate the
process by default. As a library, we should avoid terminating
the application process when error happens and just need to
return with an error.

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

lib/librte_vhost/socket.c

@@ -174,7 +174,7 @@ send_fd_message(int sockfd, char *buf, int buflen, int *fds, int fd_num)
 	}
 
 	do {
-		ret = sendmsg(sockfd, &msgh, 0);
+		ret = sendmsg(sockfd, &msgh, MSG_NOSIGNAL);
 	} while (ret < 0 && errno == EINTR);
 
 	if (ret < 0) {