staging:rtl8192u: Rename CmdID_WritePortUchar > CMD_ID_WRITE_PORT_UCHAR

Rename the enum label CmdID_WritePortUchar to CMD_ID_WRITE_PORT_UCHAR, to
clear the checkpatch issue with CamelCase. The change 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>