ixgbe: Fix comments that are out of date or formatted incorrectly

This patch corrects several comments that are either incorrect or formatted
incorrectly for multiline comments.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 1cf676b..23a4665 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -2359,7 +2359,7 @@
 	u32 eicr;
 
 	/*
-	 * Workaround for silicon errata on 82598.  Mask the interrupts
+	 * Workaround for silicon errata #26 on 82598.  Mask the interrupt
 	 * before the read of EICR.
 	 */
 	IXGBE_WRITE_REG(hw, IXGBE_EIMC, IXGBE_IRQ_CLEAR_MASK);
@@ -4381,7 +4381,11 @@
 	f_fdir->indices = min((int)num_online_cpus(), f_fdir->indices);
 	f_fdir->mask = 0;
 
-	/* Flow Director must have RSS enabled */
+	/*
+	 * Use RSS in addition to Flow Director to ensure the best
+	 * distribution of flows across cores, even when an FDIR flow
+	 * isn't matched.
+	 */
 	if ((adapter->flags & IXGBE_FLAG_RSS_ENABLED) &&
 	    (adapter->flags & IXGBE_FLAG_FDIR_HASH_CAPABLE)) {
 		adapter->num_tx_queues = f_fdir->indices;
@@ -4558,7 +4562,8 @@
 	 */
 	vector_threshold = MIN_MSIX_COUNT;
 
-	/* The more we get, the more we will assign to Tx/Rx Cleanup
+	/*
+	 * The more we get, the more we will assign to Tx/Rx Cleanup
 	 * for the separate queues...where Rx Cleanup >= Tx Cleanup.
 	 * Right now, we simply care about how many we'll get; we'll
 	 * set them up later while requesting irq's.
@@ -6996,7 +7001,7 @@
 
 	/*
 	 * need: 1 descriptor per page * PAGE_SIZE/IXGBE_MAX_DATA_PER_TXD,
-	 *       + 1 desc for skb_head_len/IXGBE_MAX_DATA_PER_TXD,
+	 *       + 1 desc for skb_headlen/IXGBE_MAX_DATA_PER_TXD,
 	 *       + 2 desc gap to keep tail from touching head,
 	 *       + 1 desc for context descriptor,
 	 * otherwise try next time