tcp: disable the repair mode only for sockets of a current process (v3)

rst_tcp_repair_sockets is filled when all sockets are collected,
but the repair mode should be disabled only for sockets which
are restored in a current process.

https://bugzilla.openvz.org/show_bug.cgi?id=3281



v2: add a comment
v3: typo fix

Fixes: 73e303c8 ('rst: Fix rst_tcp_sock memory management')
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>