grant: Fixup quoting for function permission granting if schema is given.
grant: Fixup quoting for function permission granting if schema is given.

This was missed before and found by the test.

buzzdeee/puppetlabs-postgresql,puppetlabs/puppetlabs-postgresql,puppetlabs/puppetlabs-postgresql,buzzdeee/puppetlabs-postgresql,buzzdeee/puppetlabs-postgresql,puppetlabs/puppetlabs-postgresql