atlantic: Remove warn trace message.

Remove the warn trace message - it's not a correct check here, because
the function can still be called on the device in DOWN state

Fixes: 508f2e3d

 ("net: atlantic: split rx and tx per-queue stats")
Signed-off-by: Sameer Saurabh <ssaurabh@marvell.com>
Signed-off-by: Sudarsana Reddy Kalluru <skalluru@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>