EDAC, i7core: Remove set but not used variable pvt

Remove the unused local variable pvt:

  drivers/edac/i7core_edac.c: In function 'i7core_mce_check_error':
  drivers/edac/i7core_edac.c:1818:21: warning: variable 'pvt' set but not used \
	  [-Wunused-but-set-variable]

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1537841043-108267-1-git-send-email-yuehaibing@huawei.com