fm10k: fix function header comment

The header comment included a miscopy of a C-code line, and also
mis-used Rx FIFO when it clearly meant Tx FIFO

Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Matthew Vick <matthew.vick@intel.com>
Tested-by: Krishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_mbx.c b/drivers/net/ethernet/intel/fm10k/fm10k_mbx.c
index 59faf32..e9ecfb4 100644
--- a/drivers/net/ethernet/intel/fm10k/fm10k_mbx.c
+++ b/drivers/net/ethernet/intel/fm10k/fm10k_mbx.c
@@ -326,8 +326,7 @@
  *  fm10k_mbx_write_copy - pulls data off of Tx FIFO and places it in mbmem
  *  @mbx: pointer to mailbox
  *
- *  This function will take a section of the Rx FIFO and copy it into the
-		mbx->tail--;
+ *  This function will take a section of the Tx FIFO and copy it into the
  *  mailbox memory.  The offset in mbmem is based on the lower bits of the
  *  tail and len determines the length to copy.
  **/