add failing fixture zero offset, negative length

Author: samsonasik

rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/with_zero_offset_length_negative.php.inc

@@ -9,7 +9,7 @@ class WithZeroOffsetLengthNegative
 {
     public function run(string $name)
     {
-        return substr($name, 0, -1);
+        return substr($name, 0, -5);
     }
 }
 
@@ -26,7 +26,7 @@ class WithZeroOffsetLengthNegative
 {
     public function run(string $name)
     {
-        return (string) substr($name, 0, -1);
+        return (string) substr($name, 0, -5);
     }
 }