x86/hpet: Fix /dev/rtc breakage caused by RTC cleanup

Ville Syrjälä reports "The first time I run hwclock after rebooting
I get this:

 open("/dev/rtc", O_RDONLY)              = 3
 ioctl(3, PHN_SET_REGS or RTC_UIE_ON, 0) = 0
 select(4, [3], NULL, NULL, {10, 0})     = 0 (Timeout)
 ioctl(3, PHN_NOT_OH or RTC_UIE_OFF, 0)  = 0
 close(3)                                = 0

On all subsequent runs I get this:

 open("/dev/rtc", O_RDONLY)              = 3
 ioctl(3, PHN_SET_REGS or RTC_UIE_ON, 0) = -1 EINVAL (Invalid argument)
 ioctl(3, RTC_RD_TIME, 0x7ffd76b3ae70)   = -1 EINVAL (Invalid argument)
 close(3)                                = 0"

This was caused by a stupid typo in a patch that should have been
a simple rename to move around contents of a header file, but
accidentally wrote zeroes into the rtc rather than reading from
it:

  463a863 ("char/genrtc: x86: remove remnants of asm/rtc.h")

Reported-by: Ville Syrjälä <[email protected]>
Tested-by: Jarkko Nikula <[email protected]>
Tested-by: Ville Syrjälä <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>
Cc: Alessandro Zummo <[email protected]>
Cc: Alexandre Belloni <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Fixes: 463a863 ("char/genrtc: x86: remove remnants of asm/rtc.h")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

arch/x86/kernel/hpet.c

@@ -1242,7 +1242,7 @@ irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
 	memset(&curr_time, 0, sizeof(struct rtc_time));
 
 	if (hpet_rtc_flags & (RTC_UIE | RTC_AIE))
-		mc146818_set_time(&curr_time);
+		mc146818_get_time(&curr_time);
 
 	if (hpet_rtc_flags & RTC_UIE &&
 	    curr_time.tm_sec != hpet_prev_update_sec) {