USB: android: check for platform data presence before accessing it

commit c9cb205f (USB: android: Add a new LUN as CD-ROM in mass-storage)
access platform data without checking for NULL.  This causes a kernel
panic on targets which don't have platform data.

Change-Id: I4542b0dce81604706f90b7f6e851ed47c04a941c
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
diff --git a/drivers/usb/gadget/android.c b/drivers/usb/gadget/android.c
index 2ed642a..154d523 100644
--- a/drivers/usb/gadget/android.c
+++ b/drivers/usb/gadget/android.c
@@ -1079,7 +1079,7 @@
 
 	config->fsg.nluns = 1;
 	name[0] = "lun";
-	if (dev->pdata->cdrom) {
+	if (dev->pdata && dev->pdata->cdrom) {
 		config->fsg.nluns = 2;
 		config->fsg.luns[1].cdrom = 1;
 		config->fsg.luns[1].ro = 1;