ACPI / APEI: Fix incorrect return value of ghes_proc()

BugLink: http://bugs.launchpad.net/bugs/1642968

commit 806487a8 upstream.

Although ghes_proc() tests for errors while reading the error status,
it always return success (0). Fix this by propagating the return
value.

Fixes: d334a491 (ACPI, APEI, Generic Hardware Error Source memory error support)
Signed-of-by: Punit Agrawal <punit.agrawa.@arm.com>
Tested-by: Tyler Baicar <tbaicar@codeaurora.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/acpi/apei/ghes.c

@@ -657,7 +657,7 @@ static int ghes_proc(struct ghes *ghes)
 	ghes_do_proc(ghes, ghes->estatus);
 out:
 	ghes_clear_estatus(ghes);
-	return 0;
+	return rc;
 }
 
 static void ghes_add_timer(struct ghes *ghes)