Fix build failure when XF86_SCRN_INTERFACE defined
Fix build failure when XF86_SCRN_INTERFACE defined

fixes a problem introduced with commit 22437e9

Change-Id: Ie0150f9e7f7d0507864f2db9e08a23c3200fe9eb

commshare/xf86-video-armsoc,xin3liang/xf86-video-armsoc,freedesktop-unofficial-mirror/xorg__driver__xf86-video-armsoc,OtherCrashOverride/armsoc-hardkernel,Popolon/xf86-video-armsoc,singulared/xf86-video-armsoc,apxii/xf86-video-armsoc,mdrjr/xf86-video-armsoc,singulared/xf86-video-armsoc,mmind/xf86-video-armsoc,Popolon/xf86-video-armsoc,xin3liang/xf86-video-armsoc,OtherCrashOverride/armsoc-hardkernel,apxii/xf86-video-armsoc,sbambrough/xf86-video-armsoc,mdrjr/xf86-video-armsoc,commshare/xf86-video-armsoc,freedesktop-unofficial-mirror/xorg__driver__xf86-video-armsoc,mmind/xf86-video-armsoc,sbambrough/xf86-video-armsoc