oslib-posix: rename socket_set_nonblock() to qemu_set_nonblock()

oslib-posix: rename socket_set_nonblock() to qemu_set_nonblock()

The fcntl(fd, F_SETFL, O_NONBLOCK) flag is not specific to sockets.
Rename to qemu_set_nonblock() just like qemu_set_cloexec().

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit 399f1c8f8af1f6f8b18ef4e37169c6301264e467)

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Conflicts:
	block/sheepdog.c

socket_set_block()/socket_set_nonblock() calls in different locations

	include/qemu/sockets.h

socket_set_nodelay() does not exist in v1.4.0, messes up diff context

	qemu-char.c

glib G_IO_IN events are not used in v1.4.0, messes up diff context

	savevm.c

qemu_fopen_socket() only has read mode in v1.4.0, qemu_set_block() not
necessary.

	slirp/misc.c

unportable setsockopt() calls in v1.4.0 mess up diff context

	slirp/tcp_subr.c

file was reformatted, diff context is messed up

	ui/vnc.c

old dcl->idle instead of vd->dcl.idle messes up diff context

Added:
	migration-tcp.c, migration-unix.c

qemu_fopen_socket() write mode does not exist yet, qemu_set_block() call
is needed here.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>