K 10
svn:author
V 6
brooks
K 8
svn:date
V 27
2018-03-27T15:20:03.142298Z
K 7
svn:log
V 419
Move uio enums to sys/_uio.h.

Include _uio.h instead of uio.h in several headers to reduce header
polution.

Fix a few places that relied on header polution to get the uio.h header.

I have not moved struct uio as many more things that use it rely on
header polution to get other definitions from uio.h.

Reviewed by:	cem, kib, markj
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D14811

END