drivers/edac: fix e752x correct return code

This patch changes the error code when dev0:fun1 was hidden by BIOS to one
more appropriate.

Signed-off-by: Aristeu Rozanski <aris@ruivo.org>
Signed-off-by: Mark Gross <mark.gross@intel.com>
Signed-off-by: Doug Thompson <dougthompson@xmission.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>