staging:rtl8192u: Rename CmdID_WritePortUshort > CMD_ID_WRITE_PORT_USHORT

Rename the enum label CmdID_WritePortUshort to CMD_ID_WRITE_PORT_USHORT to
clear the checkpatch warning on CamelCase naming. This is a coding style
change only and should not impact code execution.

Signed-off-by: John Whitmore <johnfwhitmore@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>