mtd: mtdoops: Fix kmsgdump parameter renaming.

When the kmsg_dumper callback parameter changed, the reason variable
in mtdoops_do_dump() was not updated accordingly.
This breaks the build with mtdoops.

Fixes: e1a261ba ("printk: Add a short description string to kmsg_dump()")
Suggested-by: Knop Ryszard <ryszard.knop@intel.com>
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Acked-by: Richard Weinberger <richard@nod.at>
Link: https://patchwork.freedesktop.org/patch/msgid/20240719152542.1554440-1-jfalempe@redhat.com

drivers/mtd/mtdoops.c

@@ -305,7 +305,7 @@ static void mtdoops_do_dump(struct kmsg_dumper *dumper,
 	struct kmsg_dump_iter iter;
 
 	/* Only dump oopses if dump_oops is set */
-	if (reason == KMSG_DUMP_OOPS && !dump_oops)
+	if (detail->reason == KMSG_DUMP_OOPS && !dump_oops)
 		return;
 
 	kmsg_dump_rewind(&iter);
@@ -317,7 +317,7 @@ static void mtdoops_do_dump(struct kmsg_dumper *dumper,
 			     record_size - sizeof(struct mtdoops_hdr), NULL);
 	clear_bit(0, &cxt->oops_buf_busy);
 
-	if (reason != KMSG_DUMP_OOPS) {
+	if (detail->reason != KMSG_DUMP_OOPS) {
 		/* Panics must be written immediately */
 		mtdoops_write(cxt, 1);
 	} else {