ixgbe: use typed min/max functions where possible

using the form min((int)var, ver)) is replaced by min_t(int, ...)

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Stephen Ko <stephen.s.ko@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>