octeon_ep_vf: introduce octep_vf_oq_next_idx() helper

Introduce octep_vf_oq_next_idx() to consolidate the repeated
ring index advance and wraparound pattern in __octep_vf_oq_process_rx().

No functional change intended.

Signed-off-by: David Carlier <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_rx.c

···
 	return new_pkts;
 }
 
+static inline u32 octep_vf_oq_next_idx(struct octep_vf_oq *oq, u32 idx)
+{
+	return (idx + 1 == oq->max_count) ? 0 : idx + 1;
+}
+
 /**
  * __octep_vf_oq_process_rx() - Process hardware Rx queue and push to stack.
  *
···
 			skb = napi_build_skb((void *)resp_hw, PAGE_SIZE);
 			skb_reserve(skb, data_offset);
 			skb_put(skb, buff_info->len);
-			read_idx++;
 			desc_used++;
-			if (read_idx == oq->max_count)
-				read_idx = 0;
+			read_idx = octep_vf_oq_next_idx(oq, read_idx);
 		} else {
 			struct skb_shared_info *shinfo;
 			u16 data_len;
···
 			 * subsequent fragments contains only data.
 			 */
 			skb_put(skb, oq->max_single_buffer_size);
-			read_idx++;
 			desc_used++;
-			if (read_idx == oq->max_count)
-				read_idx = 0;
+			read_idx = octep_vf_oq_next_idx(oq, read_idx);
 
 			shinfo = skb_shinfo(skb);
 			data_len = buff_info->len - oq->max_single_buffer_size;
···
 						buff_info->len,
 						buff_info->len);
 				buff_info->page = NULL;
-				read_idx++;
 				desc_used++;
-				if (read_idx == oq->max_count)
-					read_idx = 0;
+				read_idx = octep_vf_oq_next_idx(oq, read_idx);
 			}
 		}