Revert "tty: xilinx_uartps: Correct return value in probe"

This reverts commit eca42d4c.

During review it was rejected, so drop it from the tree.

Cc: Rajan Vaja <RAJANV@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>