Staging: rtl8192e: Rename variable OpMode

Rename variable OpMode to op_mode to fix checkpatch
warning Avoid CamelCase.

Signed-off-by: Tree Davies <tdavies@darkphysics.net>
Link: https://lore.kernel.org/r/20231225202314.31869-7-tdavies@darkphysics.net


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>