mtd: rawnand: atmel: fix possible object reference leak

mtd: rawnand: atmel: fix possible object reference leak

of_find_device_by_node() takes a reference to the struct device
when it finds a match via get_device, there is no need to call
get_device() twice.
We also should make sure to drop the reference to the device
taken by of_find_device_by_node() on driver unbind.

Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
Signed-off-by: Wen Yang <[email protected]>
Suggested-by: Boris Brezillon <[email protected]>
Reviewed-by: Boris Brezillon <[email protected]>
Reviewed-by: Miquel Raynal <[email protected]>
Acked-by: Miquel Raynal <[email protected]>
Cc: Tudor Ambarus <[email protected]>
Cc: Boris Brezillon <[email protected]>
Cc: Miquel Raynal <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: David Woodhouse <[email protected]>
Cc: Brian Norris <[email protected]>
Cc: Marek Vasut <[email protected]>
Cc: Nicolas Ferre <[email protected]>
Cc: Alexandre Belloni <[email protected]>
Cc: Ludovic Desroches <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Miquel Raynal <[email protected]>