staging: lustre: lnet: selftest: use min_t in place of min

This patch silences the checkpatch warning 'min() should
probably be min_t'

Signed-off-by: Hari Prasath Gujulan Elango <hgujulan@visteon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>