This patch removed stange logic about minusers.
Now we calculate foreign users only.

The main idea of this patch, that we bind a pipe ends to correct
descriptos immediately.

When a process X creates a pipe, we have two cases:
1. Both ends belongs to this process. It's simple, we bind both ends
   to their descriptors and we go further.
2. Only one end of a pipe belongs to this process. In this case we are
   waiting all foreign users and we go futher.
In second case we should wait, because a end which doesn't belong to
this process occupies a file descriptor, which may be used by another
pipe.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelianov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>