Don't call close() with degative fd. For consistency
simply use close_safe here. All fds touched are initialized
either to valid fd or to value < 0 which pretty good handled
by close_safe helper.

CID 996212 (#1 of 1): Argument cannot be negative (NEGATIVE_RETURNS)
10. negative_returns: "fd" is passed to a parameter that cannot be negative.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>