Staging: rtl8192u: Replace TRUE with true

This patch replaces TRUE by true, since Linux kernel has already a
boolean type, bool, defined in linux/stddef.h

Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>