slirp: Put forked exec into separate process group

Recent smb daemons tend to terminate themselves via a process group
SIGTERM. If the daemon is still in qemu's group by that time, qemu will
die as well. Avoid this by always pushing fork_exec processes into a
group of their own, not just (unused) type 2 execs.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

slirp/misc.c

@@ -153,11 +153,12 @@ fork_exec(struct socket *so, const char *ex, int do_pty)
 		return 0;
 
 	 case 0:
+                setsid();
+
 		/* Set the DISPLAY */
 		if (do_pty == 2) {
 			(void) close(master);
 #ifdef TIOCSCTTY /* XXXXX */
-			(void) setsid();
 			ioctl(s, TIOCSCTTY, (char *)NULL);
 #endif
 		} else {