MFC r298448,r298464:

MFC r298448,r298464:

r298448:

Don't leak `string` in parse_define(..) when a macro has been found
and the parser token != TOK_ASSIGN

CID: 1007187, 1007188
Obtained from: Isilon OneFS (part of r445479)

r298464:

Use `sizeof(*uuser)` instead of `sizeof(struct usm_user)` for consistency with
the rest of the users in the file

No functional change

git-svn-id: svn://svn.freebsd.org/base/stable/10@299018 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f