Some fixes for MTD drivers

[Richard Weinberger]

This series fixes some minor issues I've found while bowsing
in various MTD drivers.

[PATCH 1/6] mtd: r852: Fix device_create_file() usage
[PATCH 2/6] mtd: nandsim: Fix kasprintf() usage
[PATCH 3/6] mtd: cs553x_nand: Fix kasprintf() usage
[PATCH 4/6] mtd: docg3: Don't leak docg3->bbt in error path
[PATCH 5/6] mtd: docg3: Fix kasprintf() usage
[PATCH 6/6] mtd: docg3: Don't do ERR_PTR(0)

Thanks,
//richard