mtd: nand: sunxi: fix sunxi_nand_chips_cleanup()

The sunxi_nand_chips_cleanup() function is missing a call to list_del()
which generates a double free error.

Reported-by: Priit Laes <plaes@plaes.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: <stable@vger.kernel.org> # 3.19+
Fixes: 1fef62c1423b ("mtd: nand: add sunxi NAND flash controller support")
Tested-by: Priit Laes <plaes@plaes.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
index 279cafd..e7d333c 100644
--- a/drivers/mtd/nand/sunxi_nand.c
+++ b/drivers/mtd/nand/sunxi_nand.c
@@ -1381,6 +1381,7 @@
 					node);
 		nand_release(&chip->mtd);
 		sunxi_nand_ecc_cleanup(&chip->nand.ecc);
+		list_del(&chip->node);
 	}
 }