ixgbe: Fix compiler warning about variable being used uninitialized

tc is still throwing a warning that is could be used
uninitialized.  This fixes it, and properly formats the device ID
checks for the use of this variable.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>