pepper_hash_for_uma: Added newline to printf.

BUG=342253

Review URL: https://codereview.chromium.org/158573002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250058 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250058