pm_runtime_get_sync will increment pm usage counter even it
failed. Forgetting to pm_runtime_put_noidle will result in
reference leak in spi_mem_access_start, so we should fix it.

Fixes: f86c24f4 ("spi: spi-mem: Split spi_mem_exec_op() code")
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Link: https://lore.kernel.org/r/20201103140910.3482-1-zhangqilong3@huawei.comSigned-off-by: Mark Brown <broonie@kernel.org>