[PATCH] fix non-leader exec under ptrace

This reverts most of commit 30e0fca6c1d7d26f3f2daa4dd2b12c51dadc778a.
It broke the case of non-leader MT exec when ptraced.
I think the bug it was intended to fix was already addressed by commit
788e05a67c343fa22f2ae1d3ca264e7f15c25eaf.

Signed-off-by: Roland McGrath <roland@redhat.com>
Acked-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/signal.c b/kernel/signal.c
index b14f895..e5f8aea 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1754,9 +1754,9 @@
 			/* Let the debugger run.  */
 			ptrace_stop(signr, signr, info);
 
-			/* We're back.  Did the debugger cancel the sig or group_exit? */
+			/* We're back.  Did the debugger cancel the sig?  */
 			signr = current->exit_code;
-			if (signr == 0 || current->signal->flags & SIGNAL_GROUP_EXIT)
+			if (signr == 0)
 				continue;
 
 			current->exit_code = 0;