Close parser for incorrect manifests

parser.close() should be called in every case other than when the correct manifest is found and the open parser is returned.

Change-Id: Ibbff0b08cc73b76902382ba607f71f8ae9de41a4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5372216


Reviewed-by: Richard (Torne) Coles <torne@chromium.org>
Commit-Queue: Aashna Jena <aashnajena@google.com>
Cr-Commit-Position: refs/heads/main@{#1272925}