genirq, softirq: Use in_hardirq() instead of in_irq()

Replace the obsolete and ambiguos macro in_irq() with the new macro
in_hardirq().

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220128110727.5110-1-changbin.du@gmail.com