parallels: Add "explicit" argument to parallels_check_leak()

parallels: Add "explicit" argument to parallels_check_leak()

In the on of the next patches we need to repair leaks without changing
leaks and leaks_fixed info in res. Also we don't want to print any warning
about leaks. Add "explicit" argument to skip info changing if the argument
is false.

Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Denis V. Lunev <den@openvz.org>