Prevent quotactl calls that pass in an id of -1 from incorrectly
using the callers UID instead of the GID when performing group
operations. This could allow users to determine group quota
information for groups they are not a member of in some cases.

Rename the "uid" parameter in ufs_quotactl to "id" to better show
that it is used for more than just the uid, and to be more in line
with the naming conventions in the other quota routines.

PR: kern/33940