Currently the allocation of priv->oldaddr is not null checked which will
lead to subsequent errors when accessing priv->oldaddr.  Fix this with
a null pointer check and a return of -ENOMEM on allocation failure.
Detected with Coccinelle:
drivers/staging/rtl8192u/r8192U_core.c:1708:2-15: alloc with no test,
possible model on line 1723
Fixes: 8fc8598e61f6 ("Staging: Added Realtek rtl8192u driver to staging")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 
                priv->rx_urb[16] = usb_alloc_urb(0, GFP_KERNEL);
                priv->oldaddr = kmalloc(16, GFP_KERNEL);
+               if (!priv->oldaddr)
+                       return -ENOMEM;
                oldaddr = priv->oldaddr;
                align = ((long)oldaddr) & 3;
                if (align) {