mtd: rawnand: qcom: Remove superfluous initialization of "ret"

In all the cases, "ret" variable is assigned a value before returning it.
So there is no need to explicitly initialize it with 0.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230805174146.57006-2-manivannan.sadhasivam@linaro.org