zdtm: Mount devpts in new root

In case if we enter the new rootfs don't forget to
mount devpts, otherwise ttys can't be connected.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm/lib/ns.c

@@ -58,6 +58,18 @@ static int prepare_mntns()
 			fprintf(stderr, "mount(/proc) failed: %m\n");
 			return -1;
 		}
+		if (mkdir("/dev", 0755) && errno != EEXIST) {
+			fprintf(stderr, "mkdir(/dev) failed: %m\n");
+			return -1;
+		}
+		if (mkdir("/dev/pts", 0755) && errno != EEXIST) {
+			fprintf(stderr, "mkdir(/dev/pts) failed: %m\n");
+			return -1;
+		}
+		if (mount("pts", "/dev/pts", "devpts", MS_MGC_VAL, NULL)) {
+			fprintf(stderr, "mount(/dev/pts) failed: %m\n");
+			return -1;
+		}
 		if (fchdir(dfd)) {
 			fprintf(stderr, "fchdir() failed: %m\n");
 			return -1;