locking/qrwlock: Use 'struct qrwlock' instead of 'struct __qrwlock'

locking/qrwlock: Use 'struct qrwlock' instead of 'struct __qrwlock'

There's no good reason to keep the internal structure of struct qrwlock
hidden from qrwlock.h, particularly as it's actually needed for unlock
and ends up being abstracted independently behind the __qrwlock_write_byte()
function.

Stop pretending we can hide this stuff, and move the __qrwlock definition
into qrwlock, removing the __qrwlock_write_byte() nastiness and using the
same struct definition everywhere instead.

Signed-off-by: Will Deacon <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: [email protected]
Cc: Linus Torvalds <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Waiman Long <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>