staging:rtl8192u: Remove typedef from firmware_init_step_e - Style

Remove the typedef directive from enumerated type firmware_init_step_e
this clears the checkpatch issue with adding new types to the code.

This is a coding style change which should have no impact on runtime
code execution.

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