staging:rtl8192u: Remove typedef from enum opt_rst_type_e - Style

Remove the typedef directive from enumerated type opt_rst_type_e,
this change clears the checkpatch issue with defining new types in
the code.

This is a coding style change which should not impact runtime
code execution.

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