omap_driver: remove redundant call to xf86SetDesiredModes
omap_driver: remove redundant call to xf86SetDesiredModes

xf86SetDesiredModes is already called by OMAPEnterVT. Also,
checking of OMAPEnterVT return value.

BUG=chromium-os:34914
TEST=restart ui

Change-Id: I72e3b27594c9f4da54f093abe8bfa2655a7b7048
Signed-off-by: Mandeep Singh Baines <19acf4ef1f391f4aab404dc5703cac3632e06f3a@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/34539
Reviewed-by: Stéphane Marchesin <e16f69845633a0cf74affe1e5a677caa6296c937@chromium.org>

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