scripts/checkpatch.pl: mandate SPDX tag for Rust src files

Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 9291bc9..833f20f 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -1499,7 +1499,7 @@
 	if ($fileinfo->{action} eq "new" &&
 	    !exists $fileinfo->{facts}->{sawspdx}) {
 		if ($fileinfo->{filenew} =~
-		    /(\.(c|h|py|pl|sh|json|inc)|Makefile.*)$/) {
+		    /(\.(c|h|py|pl|sh|json|inc|rs)|Makefile.*)$/) {
 			# source code files MUST have SPDX license declared
 			ERROR("New file '" . $fileinfo->{filenew} .
 			      "' requires 'SPDX-License-Identifier'");