tests/valgrind.pm: fix warnings with no valgrind report to show

"readline() on closed filehandle $val at valgrind.pm line 45."

Closes #14977

diff --git a/tests/valgrind.pm b/tests/valgrind.pm
index a0bce30c8b33b629047e282d0dd82b9a3bb5248a..95d08a05fe970bff7c7bd8394cb3e94ea0871421 100644 (file)
--- a/tests/valgrind.pm
+++ b/tests/valgrind.pm
@@ -41,7 +41,8 @@ use File::Basename;
 sub valgrindparse {
     my ($file) = @_;
     my @o;
-    open(my $val, "<", "$file");
+    open(my $val, "<", "$file") ||
+        return;
     @o = <$val>;
     close($val);
     return @o;