mtd: parsers: qcom: Fix missing free for pparts in cleanup

Mtdpart doesn't free pparts when a cleanup function is declared.
Add missing free for pparts in cleanup function for smem to fix the
leak.

Fixes: 10f3b4d7

 ("mtd: parsers: qcom: Fix leaking of partition name")
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220116032211.9728-2-ansuelsmth@gmail.com