OMAPFB: fix error handling in omapfb_find_best_mode()

omapfb_find_best_mode() doesn't check for the return value of kmalloc.
Fix this. This also removes the smatch warning:

drivers/video/omap2/omapfb/omapfb-main.c:2256 omapfb_find_best_mode()
error: potential null dereference 'specs'.  (kzalloc returns null)
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/omap2/omapfb/omapfb-main.c

@@ -2241,12 +2241,18 @@ static int omapfb_find_best_mode(struct omap_dss_device *display,
 
 	len = 0x80 * 2;
 	edid = kmalloc(len, GFP_KERNEL);
+	if (edid == NULL)
+		return -ENOMEM;
 
 	r = display->driver->read_edid(display, edid, len);
 	if (r < 0)
 		goto err1;
 
 	specs = kzalloc(sizeof(*specs), GFP_KERNEL);
+	if (specs == NULL) {
+		r = -ENOMEM;
+		goto err1;
+	}
 
 	fb_edid_to_monspecs(edid, specs);