rust: helpers: Add dma_mapping_error() helper

Used by Apple SEP driver.

Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>

Author: WhatAmISupposedToPutHere

rust/helpers/dma-mapping.c

@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/dma-mapping.h>
+
+int rust_helper_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
+{
+	return dma_mapping_error(dev, dma_addr);
+}

rust/helpers/helpers.c

@@ -17,6 +17,7 @@
 #include "cred.c"
 #include "device.c"
 #include "dma.c"
+#include "dma-mapping.c"
 #include "drm.c"
 #include "err.c"
 #include "fs.c"