Add missing property

Signed-off-by: Ion Bazan <ion.bazan@gmail.com>

Author: IonBazan

src/Check/DiskFree.php

@@ -126,6 +126,11 @@ class DiskFree extends AbstractCheck implements CheckInterface
         3 => 1073741824, // 2^30 == 1024^3
     ];
 
+    /**
+     * The disk path to check.
+     */
+    private string $path;
+
     /**
      * @param  int|string                $size Minimum disk size in bytes or a valid byte string (IEC, SI or Jedec).
      * @param  string                    $path The disk path to check, i.e. '/tmp' or 'C:' (defaults to /)