EDAC/ghes: Remove intermediate buffer pvt->detail_location

detail_location[] is used to collect two location strings so they can
be passed as one to trace_mc_event(). Instead of having an extra copy
step, assemble the location string in other_detail[] from the
beginning.

Using other_detail[] to call trace_mc_event() is now the same as in
edac_mc.c and code can be unified.

Signed-off-by: Robert Richter <rrichter@marvell.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20191106093239.25517-12-rrichter@marvell.com