mtd: nand: free vendor-specific resources in init failure paths

If we fail any time after calling nand_detect(), then we don't call the
vendor-specific ->cleanup() callback, and we'll leak any resources the
vendor-specific code might have allocated.

Mark the "fix" against the first commit that started allocating anything
in ->init().

Fixes: 626994e0 ("mtd: nand: hynix: Add read-retry support for 1x nm MLC NANDs")
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>