This reduces the number of CONFIG_VNC #ifdefs in the vl.c code.
The only user-visible difference is that this will make QEMU
complain about syntax when using "-display vnc" ("VNC requires a
display argument vnc=<display>") even if CONFIG_VNC is disabled.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
f8c75b2486