Fix a few perlcritic warnings

bin/efa

@@ -60,8 +60,8 @@ sub check_no_connections {
 	my $err_node = $full_tree->findnodes($xp_err_img)->[0];
 
 	if ($err_node) {
-		say {*STDERR} "Looks like efa.vrr.de showed an error.";
-		say {*STDERR} "I will now try to dump the error message:";
+		say {*STDERR} 'Looks like efa.vrr.de showed an error.';
+		say {*STDERR} 'I will now try to dump the error message:';
 
 		say {*STDERR} $err_node->parentNode()->parentNode()->textContent();
 
@@ -270,7 +270,7 @@ sub parse_tree {
 	}
 	else {
 		say {*STDERR}
-			"efa.vrr.de returned no connections, check your input data.";
+			'efa.vrr.de returned no connections, check your input data.';
 		exit 3;
 	}
 }
@@ -346,7 +346,7 @@ $post{type_destination} = $to_type;
 $post{type_via} = $via_type;
 
 if ($test_parse) {
-	local $/;
+	local $/ = undef;
 	$content = <STDIN>;
 }
 else {