EDAC: i7300_edac: rename a kernel-doc var description

One var was renamed, but the associated kernel-doc markup still
points to the old name.

Acked-by: Borislav Petkov <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>