[FaceRestTestUtils] Remove an unused paramter in _assertUpdateRecord().

The 1st paramter: JSONParserAgent *parser is not used as both input
and output. In addition, this patch also fixes the allocated
JSONParserAgent instance stored in the variable.
Merge pull request #452 from project-hatohol/fix-test-face-rest-utils-update-record

[FaceRestTestUtils] Remove an unused paramter in _assertUpdateRecord().