openprom: Squelch useless GCC warning.

drivers/sbus/char/openprom.c: In function ‘openprom_sunos_ioctl’:
drivers/sbus/char/openprom.c:306: warning: ‘opp’ may be used uninitialized in this function

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/sbus/char/openprom.c b/drivers/sbus/char/openprom.c
index 124f660..75ac19b 100644
--- a/drivers/sbus/char/openprom.c
+++ b/drivers/sbus/char/openprom.c
@@ -303,7 +303,7 @@
 				struct device_node *dp)
 {
 	DATA *data = file->private_data;
-	struct openpromio *opp;
+	struct openpromio *opp = NULL;
 	int bufsize, error = 0;
 	static int cnt;
 	void __user *argp = (void __user *)arg;