[Coverity] Fix possible leak.
[Coverity] Fix possible leak.

If the first open returns a file handle of 0, it could be leaked (if PLATFORM_FILE_OPEN_ALWAYS is set too)

In general, fixed so that file handle of 0 is treated as a file handle, not as error code.

CID=101981

BUG=
TEST=

Review URL: https://chromiumcodereview.appspot.com/9873005

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@129659 0039d316-1c4b-4281-b951-d872f2087c98

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