hardirq.h: remove now-empty #ifdef/#endif pair

Commit 451a3c24b013 ("BKL: remove extraneous #include <smp_lock.h>")
removed the #include line that was the only thing that was surrounded by
the #ifdef/#endif.

So now that #ifdef is guarding nothing at all. Just remove it.

Reported-by: Byeong-ryeol Kim <brofkims@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

-2
-2
include/linux/hardirq.h
··· 2 #define LINUX_HARDIRQ_H 3 4 #include <linux/preempt.h> 5 - #ifdef CONFIG_PREEMPT 6 - #endif 7 #include <linux/lockdep.h> 8 #include <linux/ftrace_irq.h> 9 #include <asm/hardirq.h>
··· 2 #define LINUX_HARDIRQ_H 3 4 #include <linux/preempt.h> 5 #include <linux/lockdep.h> 6 #include <linux/ftrace_irq.h> 7 #include <asm/hardirq.h>