tick/nohz: Don't shutdown the lowres tick from itself

In lowres dynticks mode, just like in highres dynticks mode, when there
is no tick to program in the future, the tick eventually gets
deactivated either:

  * From the idle loop if in idle mode.
  * From the IRQ exit if in full dynticks mode.

Therefore there is no need to deactivate it from the tick itself. This
just just brings more overhead in the idle tick path for no reason.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lore.kernel.org/r/20230912104406.312185-4-frederic@kernel.org