dmaengine: Replace zero-length array with flexible-array

There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://github.com/KSPP/linux/issues/21

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
diff --git a/drivers/dma/milbeaut-xdmac.c b/drivers/dma/milbeaut-xdmac.c
index ab3d2f3..85a5972 100644
--- a/drivers/dma/milbeaut-xdmac.c
+++ b/drivers/dma/milbeaut-xdmac.c
@@ -74,7 +74,7 @@ struct milbeaut_xdmac_chan {
 struct milbeaut_xdmac_device {
 	struct dma_device ddev;
 	void __iomem *reg_base;
-	struct milbeaut_xdmac_chan channels[0];
+	struct milbeaut_xdmac_chan channels[];
 };
 
 static struct milbeaut_xdmac_chan *