scripts/dtc: Update to upstream version 9d3649bd3be245c9

Sync dtc with upstream as of commit 9d3649bd3be2 (Add testcases for
fdt_path_offset_namelen()).

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: devicetree@vger.kernel.org
diff --git a/scripts/dtc/libfdt/libfdt_internal.h b/scripts/dtc/libfdt/libfdt_internal.h
index 381133b..02cfa6f 100644
--- a/scripts/dtc/libfdt/libfdt_internal.h
+++ b/scripts/dtc/libfdt/libfdt_internal.h
@@ -57,9 +57,9 @@
 
 #define FDT_CHECK_HEADER(fdt) \
 	{ \
-		int err; \
-		if ((err = fdt_check_header(fdt)) != 0) \
-			return err; \
+		int __err; \
+		if ((__err = fdt_check_header(fdt)) != 0) \
+			return __err; \
 	}
 
 int _fdt_check_node_offset(const void *fdt, int offset);