mtd: rawnand: omap_elm: Fix runtime PM imbalance on error

mtd: rawnand: omap_elm: Fix runtime PM imbalance on error

[ Upstream commit 37f7212148cf1d796135cdf8d0c7fee13067674b ]

pm_runtime_get_sync() increments the runtime PM usage counter even
when it returns an error code. Thus a pairing decrement is needed on
the error handling path to keep the counter balanced.

Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200522104008.28340-1-dinghao.liu@zju.edu.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>