ice: skip NULL check against XDP prog in ZC path

Whole zero-copy variant of clean Rx IRQ is executed when xsk_pool is
attached to rx_ring and it can happen only when XDP program is present
on interface. Therefore it is safe to assume that program is always
!NULL and there is no need for checking it in ice_run_xdp_zc.

Reviewed-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Kiran Bhandare <kiranx.bhandare@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/ice/ice_xsk.c

@@ -467,11 +467,10 @@ ice_run_xdp_zc(struct ice_ring *rx_ring, struct xdp_buff *xdp)
 	u32 act;
 
 	rcu_read_lock();
+	/* ZC patch is enabled only when XDP program is set,
+	 * so here it can not be NULL
+	 */
 	xdp_prog = READ_ONCE(rx_ring->xdp_prog);
-	if (!xdp_prog) {
-		rcu_read_unlock();
-		return ICE_XDP_PASS;
-	}
 
 	act = bpf_prog_run_xdp(xdp_prog, xdp);
 	switch (act) {