sys/vm: remove several other uses of OBJT_SWAP_TMPFS

Mostly in cases where OBJ_SWAP flag works as well, or by reversing the
condition so that object types can be listed.

Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D30168