[PATCH:xf86-video-fbdev] Use #ifdef instead of #if to avoid build error

[Adam Jackson]

On Sun, 2018-03-04 at 17:34 -0800, Alan Coopersmith wrote:
> fbdev.c:491:21: error: #if with no expression
>  #if HAVE_SHADOW_3224
>                      ^
> 
> Signed-off-by: Alan Coopersmith <alan.coopersmith at oracle.com>

Merged, thanks:

remote: I: patch #207943 updated using rev 9af7f81534aa03fe01d88786805b00729ac321e9.
remote: I: 1 patch(es) updated to state Accepted.
To git+ssh://git.freedesktop.org/git/xorg/driver/xf86-video-fbdev
   e0bce0d..9af7f81  master -> master

- ajax