nss: fix order of parenthesis.

Thanks to PVS-Studio for finding this.

BUG=324701

Review URL: https://codereview.chromium.org/99423002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238438 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238438