staging: rtl8188eu: remove implicit bool->int conversions

Implicit type conversions are bad; they hinder readability of code and have
potential to cause bugs. Here the variable wait_ack is always supplied a bool
value while in function declarations it is defined as an int type. Fix it by
defining wait_ack a bool type in all usages.

Signed-off-by: Aishwarya Pant <aishpant@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>