i40e: drop misleading function comments

i40e_cleanup_headers has a statement about check against skb being
linear or not which is not relevant anymore, so let's remove it.

Same case for i40e_can_reuse_rx_page, it references things that are not
present there anymore.
Reviewed-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/i40e/i40e_txrx.c

@@ -1963,9 +1963,6 @@ void i40e_process_skb_fields(struct i40e_ring *rx_ring,
  * @skb: pointer to current skb being fixed
  * @rx_desc: pointer to the EOP Rx descriptor
  *
- * Also address the case where we are pulling data in on pages only
- * and as such no data is present in the skb header.
- *
  * In addition if skb is not at least 60 bytes we need to pad it so that
  * it is large enough to qualify as a valid Ethernet frame.
  *
@@ -1998,33 +1995,15 @@ static bool i40e_cleanup_headers(struct i40e_ring *rx_ring, struct sk_buff *skb,
 }
 
 /**
- * i40e_can_reuse_rx_page - Determine if this page can be reused by
- * the adapter for another receive
- *
+ * i40e_can_reuse_rx_page - Determine if page can be reused for another Rx
  * @rx_buffer: buffer containing the page
  * @rx_buffer_pgcnt: buffer page refcount pre xdp_do_redirect() call
  *
- * If page is reusable, rx_buffer->page_offset is adjusted to point to
- * an unused region in the page.
- *
- * For small pages, @truesize will be a constant value, half the size
- * of the memory at page.  We'll attempt to alternate between high and
- * low halves of the page, with one half ready for use by the hardware
- * and the other half being consumed by the stack.  We use the page
- * ref count to determine whether the stack has finished consuming the
- * portion of this page that was passed up with a previous packet.  If
- * the page ref count is >1, we'll assume the "other" half page is
- * still busy, and this page cannot be reused.
- *
- * For larger pages, @truesize will be the actual space used by the
- * received packet (adjusted upward to an even multiple of the cache
- * line size).  This will advance through the page by the amount
- * actually consumed by the received packets while there is still
- * space for a buffer.  Each region of larger pages will be used at
- * most once, after which the page will not be reused.
- *
- * In either case, if the page is reusable its refcount is increased.
- **/
+ * If page is reusable, we have a green light for calling i40e_reuse_rx_page,
+ * which will assign the current buffer to the buffer that next_to_alloc is
+ * pointing to; otherwise, the DMA mapping needs to be destroyed and
+ * page freed
+ */
 static bool i40e_can_reuse_rx_page(struct i40e_rx_buffer *rx_buffer,
 				   int rx_buffer_pgcnt)
 {