net: usb: fix memory leak in smsc75xx_bind

In the Linux kernel, the following vulnerability has been resolved:

net: usb: fix memory leak in smsc75xx_bind

Syzbot reported memory leak in smsc75xx_bind().

The problem was is non-freed memory in case of

errors after memory allocation.

backtrace:

[<ffffffff84245b62>] kmalloc include/linux/slab.h:556 [inline]

[<ffffffff84245b62>] kzalloc include/linux/slab.h:686 [inline]

[<ffffffff84245b62>] smsc75xx_bind+0x7a/0x334 drivers/net/usb/smsc75xx.c:1460

[<ffffffff82b5b2e6>] usbnet_probe+0x3b6/0xc30 drivers/net/usb/usbnet.c:1728