Since on system with hybrid cards, the nvidia card might not be connecting to
the screen, so Xf86SetDisiredMode could fail, which results in a fatal error
for Xserver:
[ 91825.257] (II) NOUVEAU(G0): NVEnterVT is called.
[ 91825.258] 
Fatal server error:
[ 91825.258] EnterVT failed for gpu screen 0


The following dirty hack fixes the problem. We should check for the connected
screen before setting mode, but I don't know how to do that, since this is my
first time to look at nouveau code.

--- nv_driver-orig.c    2013-03-29 17:19:34.876953461 -0400
+++ nv_driver.c    2013-03-29 17:20:15.810287942 -0400
@@ -407,8 +407,7 @@
     if (ret)
         ErrorF("Unable to get master: %s\n", strerror(errno));

-    if (!xf86SetDesiredModes(pScrn))
-        return FALSE;
+    xf86SetDesiredModes(pScrn);

     if (pNv->overlayAdaptor && pNv->Architecture != NV_ARCH_04)
         NV10WriteOverlayParameters(pScrn);