Adds null check for DisplayStatus (Stefano Stabellini)

Allocate a DisplaySurface in dumb_display_init if none else does it.
The DisplaySurface will be used for the qemu monitor, serial and
parallel ports, etc.
Signed-off-by: NAndrew May  <acmay@acmay.homeip.net>
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6387 c046a42c-6fe2-441c-8c8c-71466251a162

vl.c

@@ -2778,6 +2778,11 @@ DisplayState *get_displaystate(void)
 static void dumb_display_init(void)
 {
     DisplayState *ds = qemu_mallocz(sizeof(DisplayState));
+    if (ds == NULL) {
+        fprintf(stderr, "dumb_display_init: DisplayState allocation failed\n");
+        exit(1);
+    }
+    ds->surface = qemu_create_displaysurface(640, 480, 32, 640 * 4);
     register_displaystate(ds);
 }