In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Muli Ben-Yehuda <mulix@mulix.org>
Cc: Jon Mason <jdmason@kudzu.us>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: iommu@lists.linux-foundation.org
Signed-off-by: NKees Cook <keescook@chromium.org>