net/ixgbe: improve link state check on VF

net/ixgbe: improve link state check on VF

In current implementation, when checking VF link state, PF state
is checked too, although the function has a parameter to tell
if PF state checking is needed.
But in some scenario, user may not care about the PF state.
This patch enables the unused parameter to only check the VF
link state.

Signed-off-by: Liang-Min Larry Wang <liang-min.wang@intel.com>
Acked-by: Wenzhuo Lu <wenzhuo.lu@intel.com>