util/lint/checkpatch.pl: Update lines related to CONST_STRUCT

Update to v5.18-2 version.

Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Change-Id: I0fe2ec6a74a4b8c70452fbf05d534a37e1ea2c26
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63582
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin L Roth <martinroth@google.com>
diff --git a/util/lint/checkpatch.pl b/util/lint/checkpatch.pl
index 8275daa..81fda35 100755
--- a/util/lint/checkpatch.pl
+++ b/util/lint/checkpatch.pl
@@ -867,9 +867,11 @@
 	return 0;
 }
 
-my $const_structs = "";
-read_words(\$const_structs, $conststructsfile)
-    or warn "No structs that should be const will be found - file '$conststructsfile': $!\n";
+my $const_structs;
+if (show_type("CONST_STRUCT")) {
+	read_words(\$const_structs, $conststructsfile)
+	    or warn "No structs that should be const will be found - file '$conststructsfile': $!\n";
+}
 
 my $typeOtherTypedefs = "";
 if (length($typedefsfile)) {
@@ -6603,7 +6605,8 @@
 
 # check for various structs that are normally const (ops, kgdb, device_tree)
 # and avoid what seem like struct definitions 'struct foo {'
-		if ($line !~ /\bconst\b/ &&
+		if (defined($const_structs) &&
+		    $line !~ /\bconst\b/ &&
 		    $line =~ /\bstruct\s+($const_structs)\b(?!\s*\{)/) {
 			WARN("CONST_STRUCT",
 			     "struct $1 should normally be const\n" . $herecurr);