Fix warnings on missing prototypes:
> ../hw/xfree86/os-support/bsd/bsd_VTsw.c:56:20: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
> xf86VTSwitchPending()
> ^
> void
> ../hw/xfree86/os-support/bsd/bsd_VTsw.c:67:17: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
> xf86VTSwitchAway()
> ^
> void
> ../hw/xfree86/os-support/bsd/bsd_VTsw.c:82:15: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
> xf86VTSwitchTo()
> ^
> void
> ../hw/xfree86/os-support/bsd/bsd_init.c:155:16: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
> xf86OpenConsole()
> ^
> void
> ../hw/xfree86/os-support/bsd/bsd_init.c:322:15: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
> xf86OpenPccons()
> ^
> void
> ../hw/xfree86/os-support/bsd/bsd_init.c:347:16: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
> xf86OpenSyscons()
> ^
> void
> ../hw/xfree86/os-support/bsd/bsd_init.c:453:13: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
> xf86OpenPcvt()
> ^
> void
> ../hw/xfree86/os-support/bsd/bsd_init.c:596:17: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
> xf86CloseConsole()
> ^
> void
> ../hw/xfree86/os-support/bsd/bsd_init.c:673:11: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
> xf86UseMsg()
> ^
> void
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1428>