all: gcc warning clean round 4
* remove unused variable
* move static function from h into cpp
* Initialized hw_by_page to 0xFFFFFFFF instead of -1 (number must be a positive integer)
* Use a s32 fore m_current_lsn instead of u32 (use -1 as error code)
Bonus: a couple of fix for clang compiler (doesn't mean that it fully compile with clang)
* remove useless __debugbreak on linux
* use short for 16bits atomic function


git-svn-id: http://pcsx2.googlecode.com/svn/trunk@5695 96395faa-99c1-11dd-bbfe-3dabce05a288