Nobody checks the error flag on jffs2 folios, so stop setting and
clearing it.  We can also remove the call to clear the uptodate
flag; it will already be clear.

Convert one of these into a call to mapping_set_error() which will
actually be checked by other parts of the kernel.

Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20240530202110.2653630-9-willy@infradead.orgTested-by: Zhihao Cheng <chengzhihao1@huawei.com>
Acked-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>