hrtimer: remove unneeded kallsyms include

hrtimer does not seem to use any of kallsyms functions/defines.

Link: http://lkml.kernel.org/r/20171208025616.16267-9-sergey.senozhatsky@gmail.comSigned-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kernel/time/hrtimer.c

@@ -37,7 +37,6 @@
 #include <linux/hrtimer.h>
 #include <linux/notifier.h>
 #include <linux/syscalls.h>
-#include <linux/kallsyms.h>
 #include <linux/interrupt.h>
 #include <linux/tick.h>
 #include <linux/seq_file.h>