i40e: Remove MSIx only if created

When cleaning up the interrupt handling, clean up the IRQs only if
we actually got them set up.  There are a couple of error recovery
paths that were violating this and causing the kernel a bit of
indigestion.

Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Reviewed-by: Williams, Mitch A <mitch.a.williams@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -4164,7 +4164,7 @@ static void i40e_clear_interrupt_scheme(struct i40e_pf *pf)
 	int i;
 
 	i40e_stop_misc_vector(pf);
-	if (pf->flags & I40E_FLAG_MSIX_ENABLED) {
+	if (pf->flags & I40E_FLAG_MSIX_ENABLED && pf->msix_entries) {
 		synchronize_irq(pf->msix_entries[0].vector);
 		free_irq(pf->msix_entries[0].vector, pf);
 	}