SLES grain fix (#3275)

The 'os' grain in SLES 11 SP2 is 'SUSE  Enterprise Server' (two spaces).
Tried to fix this a couple days ago but didn't notice the extra space
after 'SUSE'. See the following:

https://github.com/saltstack/salt/issues/3275#issuecomment-12425372
Merge pull request #3318 from archtaku/develop

SLES grain fix (#3275)