lockdep: Fix preemption WARN for spurious IRQ-enable

It is valid (albeit uncommon) to call local_irq_enable() without first
having called local_irq_disable(). In this case we enter
lockdep_hardirqs_on*() with IRQs enabled and trip a preemption warning
for using __this_cpu_read().

Use this_cpu_read() instead to avoid the warning.

Fixes: 4d004099 ("lockdep: Fix lockdep recursion")
Reported-by:  <syzbot+53f8ce8bbc07924b6417@syzkaller.appspotmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>