iomap: treat inline data in iomap_writepage_map as an I/O error

iomap_writepage_map aready warns about inline data, but then just ignores
it.  Treat it as an error and return -EIO.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231207072710.176093-3-hch@lst.deSigned-off-by: Christian Brauner <brauner@kernel.org>

fs/iomap/buffered-io.c

@@ -1808,8 +1808,10 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc,
 		if (error)
 			break;
 		trace_iomap_writepage_map(inode, &wpc->iomap);
-		if (WARN_ON_ONCE(wpc->iomap.type == IOMAP_INLINE))
-			continue;
+		if (WARN_ON_ONCE(wpc->iomap.type == IOMAP_INLINE)) {
+			error = -EIO;
+			break;
+		}
 		if (wpc->iomap.type == IOMAP_HOLE)
 			continue;
 		iomap_add_to_ioend(inode, pos, folio, ifs, wpc, wbc,