amd-xgbe: Remove an unneeded semicolon on a switch statement

Remove an unneeded semicolon at the end of a switch statement block.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>