r8152: Fix error path in open function

r8152: Fix error path in open function

If usb_submit_urb() called from the open function fails, the following
crash may be observed.

r8152 8-1:1.0 eth0: intr_urb submit failed: -19
...
r8152 8-1:1.0 eth0: v1.08.3
Unable to handle kernel paging request at virtual address 6b6b6b6b6b6b6b7b
pgd = ffffffc0e7305000
[6b6b6b6b6b6b6b7b] *pgd=0000000000000000, *pud=0000000000000000
Internal error: Oops: 96000004 [#1] PREEMPT SMP
...
PC is at notifier_chain_register+0x2c/0x58
LR is at blocking_notifier_chain_register+0x54/0x70
...
Call trace:
[<ffffffc0002407f8>] notifier_chain_register+0x2c/0x58
[<ffffffc000240bdc>] blocking_notifier_chain_register+0x54/0x70
[<ffffffc00026991c>] register_pm_notifier+0x24/0x2c
[<ffffffbffc183200>] rtl8152_open+0x3dc/0x3f8 [r8152]
[<ffffffc000808000>] __dev_open+0xac/0x104
[<ffffffc0008082f8>] __dev_change_flags+0xb0/0x148
[<ffffffc0008083c4>] dev_change_flags+0x34/0x70
[<ffffffc000818344>] do_setlink+0x2c8/0x888
[<ffffffc0008199d4>] rtnl_newlink+0x328/0x644
[<ffffffc000819e98>] rtnetlink_rcv_msg+0x1a8/0x1d4
[<ffffffc0008373c8>] netlink_rcv_skb+0x68/0xd0
[<ffffffc000817990>] rtnetlink_rcv+0x2c/0x3c
[<ffffffc000836d1c>] netlink_unicast+0x16c/0x234
[<ffffffc00083720c>] netlink_sendmsg+0x340/0x364
[<ffffffc0007e85d0>] sock_sendmsg+0x48/0x60
[<ffffffc0007e9c30>] SyS_sendto+0xe0/0x120
[<ffffffc0007e9cb0>] SyS_send+0x40/0x4c
[<ffffffc000203e34>] el0_svc_naked+0x24/0x28

Clean up error handling to avoid registering the notifier if the open
function is going to fail.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>