drivers/rtc/rtc-efi.c: avoid subtracting day twice when computing year days

Compared source code of rtc-lib.c::rtc_year_days() with
efirtc.c::rtc_year_days(), found the code in rtc-efi decreases value of
day twice when it computing year days.  rtc-lib.c::rtc_year_days() has
already decrease days and return the year days from 0 to 365.

Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>