[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=

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=129659

[darin (slow to review), 2012-03-27 23:24:25]

LGTM

[commit-bot: I haz the power, 2012-03-28 02:01:21]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/groby@chromium.org/9873005/1

[commit-bot: I haz the power, 2012-03-28 06:27:34]

Try job failure for 9873005-1 (retry) (retry) on win_rel for step
"browser_tests".
It's a second try, previously, step "browser_tests" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[commit-bot: I haz the power, 2012-03-28 16:57:11]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/groby@chromium.org/9873005/1

[commit-bot: I haz the power, 2012-03-28 22:46:52]

Try job failure for 9873005-1 (retry) (retry) (retry) on win_rel for step
"browser_tests".
It's a second try, previously, step "browser_tests" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...