Remove casting the values returned by dma_alloc_coherent.
Signed-off-by: NXu Wang <vulab@iscas.ac.cn>
Link: https://lore.kernel.org/r/20201120083054.8973-1-vulab@iscas.ac.cnSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>