lockdep: Delete local_irq_enable_in_hardirq()

No more users and there is no desire to grow new ones.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/8735hir0j4.ffs@tglx