dmaengine: sdxi: context: Handle failed completion allocations

Check for failed sdxi_completion_alloc() and return early in
sdxi_start_cxt, sdxi_stop_cxt.

Signed-off-by: Nathan Lynch <nathan.lynch@amd.com>

Author: nathanlynch

drivers/dma/sdxi/context.c

@@ -406,6 +406,9 @@ int sdxi_start_cxt(struct sdxi_cxt *cxt)
 	struct sdxi_completion *sc __free(sdxi_completion) =
 		sdxi_completion_alloc(cxt->sdxi);
 
+	if (!sc)
+		return -ENOMEM;
+
 	/* This is not how to start the admin context. */
 	if (WARN_ON(adm == cxt))
 		return -EINVAL;
@@ -438,6 +441,9 @@ void sdxi_stop_cxt(struct sdxi_cxt *cxt)
 	struct sdxi_completion *sc __free(sdxi_completion) =
 		sdxi_completion_alloc(cxt->sdxi);
 
+	if (!sc)
+		return;
+
 	/* This is not how to stop the admin context. */
 	if (WARN_ON(adm == cxt))
 		return;