staging: rtl8192u: fix macros in r8192U.h

This patch fixes the macros in r8192U.h.
More specifically:

1) removes the ';' from the end of the macro definition
   and changes according the files that are affected by
   this change by adding ';' at the end of the macro call
2) replaces printk with pr_debug, when applicable
3) replaces __FUNCTION__ with __func__
4) fixes the framing when the macro contains complex expressions
5) renames macro 'assert' as 'RTL9192U_ASSERT', so that it
   cannot be confused with the c function assert(), and changes
   accordingly the files affected by this change

Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>