staging: rtl8188eu: dont mix success and error path

Success and error path was mixed. Separate them by directly returning 0
from the success path. In the process remove the variable which became
unused.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>