locking: Apply contention tracepoints in the slow path Adding the lock contention tracepoints in various lock function slow paths. Note that each arch can define spinlock differently, I only added it only to the generic qspinlock for now. Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org>