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

include/linux/interrupt.h

@@ -222,24 +222,6 @@ devm_request_any_context_irq(struct device *dev, unsigned int irq,
 
 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
 
-/*
- * On lockdep we dont want to enable hardirqs in hardirq
- * context. Use local_irq_enable_in_hardirq() to annotate
- * kernel code that has to do this nevertheless (pretty much
- * the only valid case is for old/broken hardware that is
- * insanely slow).
- *
- * NOTE: in theory this might break fragile code that relies
- * on hardirq delivery - in practice we dont seem to have such
- * places left. So the only effect should be slightly increased
- * irqs-off latencies.
- */
-#ifdef CONFIG_LOCKDEP
-# define local_irq_enable_in_hardirq()	do { } while (0)
-#else
-# define local_irq_enable_in_hardirq()	local_irq_enable()
-#endif
-
 bool irq_has_action(unsigned int irq);
 extern void disable_irq_nosync(unsigned int irq);
 extern bool disable_hardirq(unsigned int irq);