lock_timer() conditionally grabs it_lock in case of returning non-NULL
but unlock_timer() releases it unconditionally. This leads sparse to
complain about the lock context imbalance. Rename and wrap lock_timer
using __cond_lock() macro to make sparse happy.
Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>