Fixing bug where the file handle is not closed properly because the p…

…arentheses are left off the call, telling Python to return a method but not call the method.

bin/ansible-vault

@@ -107,7 +107,7 @@ def get_opt(options, k, defval=""):
 def _read_password(filename):
     f = open(filename, "rb")
     data = f.read()
-    f.close
+    f.close()
     data = data.strip()
     return data