vm/vmm: don't start separate process for console
vm/vmm: don't start separate process for console

vmctl console fails from time to time with:

vmctl: console not found

Probably there is some race (most of these things assume
that there is a human typing commands with delays).

Also, vmctl start can connect to console itself with -c flag.
So use that because it both solves the console race and
also makes code much more similar to other VM implementations (qemu, gvisor).
This also eliminates 3 additional goroutines per VM.

xairy/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller