vm_pageout: Print a more accurate message to the console before an OOM kill
Previously we'd always print "out of swap space." This can be misleading, as there are other reasons an OOM kill can be triggered. In particular, it's entirely possible to trigger an OOM kill on a system with plenty of free swap space. Reviewed by: kib MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D33810