ice: cleanup vf_id signedness

The vf_id variable is dealt with in the code in inconsistent
ways of sign usage, preventing compilation with -Werror=sign-compare.
Fix this problem in the code by always treating vf_id as unsigned, since
there are no valid values of vf_id that are negative.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ice/ice.h

@@ -371,7 +371,7 @@ struct ice_pf {
 	struct ice_sw *first_sw;	/* first switch created by firmware */
 	/* Virtchnl/SR-IOV config info */
 	struct ice_vf *vf;
-	int num_alloc_vfs;		/* actual number of VFs allocated */
+	u16 num_alloc_vfs;		/* actual number of VFs allocated */
 	u16 num_vfs_supported;		/* num VFs supported for this PF */
 	u16 num_qps_per_vf;
 	u16 num_msix_per_vf;