igbvf: cleanup msleep() and min/max() usage

Fixed a few cases of when we used msleep() when we should have been
using usleep_range().  Also updated the usage of min/max() to use
min_t/max_t().

Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>