EDAC: Remove misleading comment in struct edac_raw_error_desc

There never has been such function edac_raw_error_desc_clean() and in
function ghes_edac_report_mem_error() the whole struct is zero'ed
including the string arrays. Remove that comment.

Signed-off-by: Robert Richter <rrichter@marvell.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20191106093239.25517-9-rrichter@marvell.com