ixgbe: fix namespace issue with ixgbe_dcb_txq_to_tc

We didn't need the prototype and it was causing namespace complaints so
I made it static.
Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Tested-by: Stephen Ko <stephen.s.ko@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ixgbe/ixgbe.h

@@ -525,7 +525,6 @@ extern void ixgbe_unmap_and_free_tx_resource(struct ixgbe_ring *,
 extern void ixgbe_alloc_rx_buffers(struct ixgbe_ring *, u16);
 extern void ixgbe_write_eitr(struct ixgbe_q_vector *);
 extern int ethtool_ioctl(struct ifreq *ifr);
-extern u8 ixgbe_dcb_txq_to_tc(struct ixgbe_adapter *adapter, u8 index);
 extern s32 ixgbe_reinit_fdir_tables_82599(struct ixgbe_hw *hw);
 extern s32 ixgbe_init_fdir_signature_82599(struct ixgbe_hw *hw, u32 pballoc);
 extern s32 ixgbe_init_fdir_perfect_82599(struct ixgbe_hw *hw, u32 pballoc);

drivers/net/ixgbe/ixgbe_main.c

@@ -648,7 +648,7 @@ void ixgbe_unmap_and_free_tx_resource(struct ixgbe_ring *tx_ring,
  *
  * Returns : a tc index for use in range 0-7, or 0-3
  */
-u8 ixgbe_dcb_txq_to_tc(struct ixgbe_adapter *adapter, u8 reg_idx)
+static u8 ixgbe_dcb_txq_to_tc(struct ixgbe_adapter *adapter, u8 reg_idx)
 {
 	int tc = -1;
 	int dcb_i = adapter->ring_feature[RING_F_DCB].indices;