Fixing kernel crash when doing ifconfig down and up in a loop,

[ 124.028237] Call trace:
[ 124.030670] [<ffffffc000367ce0>] memcpy+0x20/0x180
[ 124.035436] [<ffffffc00053c250>] skb_clone+0x3c/0xa8
[ 124.040374] [<ffffffc00053ffa4>] __skb_tstamp_tx+0xc0/0x118
[ 124.045918] [<ffffffc00054000c>] skb_tstamp_tx+0x10/0x1c
[ 124.051203] [<ffffffc00049bc84>] xgene_enet_start_xmit+0x2e4/0x33c
[ 124.057352] [<ffffffc00054fc20>] dev_hard_start_xmit+0x2e8/0x400
[ 124.063327] [<ffffffc00056cb14>] sch_direct_xmit+0x90/0x1d4
[ 124.068870] [<ffffffc000550100>] __dev_queue_xmit+0x28c/0x498
[ 124.074585] [<ffffffc00055031c>] dev_queue_xmit_sk+0x10/0x1c
[ 124.080216] [<ffffffc0005c3f14>] ip_finish_output2+0x3d0/0x438
[ 124.086017] [<ffffffc0005c5794>] ip_finish_output+0x198/0x1ac
[ 124.091732] [<ffffffc0005c61d4>] ip_output+0xec/0x164
[ 124.096755] [<ffffffc0005c5910>] ip_local_out_sk+0x38/0x48
[ 124.102211] [<ffffffc0005c5d84>] ip_queue_xmit+0x288/0x330
[ 124.107668] [<ffffffc0005da8bc>] tcp_transmit_skb+0x908/0x964
[ 124.113383] [<ffffffc0005dc0d4>] tcp_send_ack+0x128/0x138
[ 124.118753] [<ffffffc0005d1580>] __tcp_ack_snd_check+0x5c/0x94
[ 124.124555] [<ffffffc0005d7a0c>] tcp_rcv_established+0x554/0x68c
[ 124.130530] [<ffffffc0005df0d4>] tcp_v4_do_rcv+0xa4/0x37c
[ 124.135900] [<ffffffc000539430>] release_sock+0xb4/0x150
[ 124.141184] [<ffffffc0005cdf88>] tcp_recvmsg+0x448/0x9e0
[ 124.146468] [<ffffffc0005f2f3c>] inet_recvmsg+0xa0/0xc0
[ 124.151666] [<ffffffc000533660>] sock_recvmsg+0x10/0x1c
[ 124.156863] [<ffffffc0005370d4>] SyS_recvfrom+0xa4/0xf8
[ 124.162061] Code: f2400c84 540001c0 cb040042 36000064 (38401423)
[ 124.168133] ---[ end trace 7ab2550372e8a65b ]---

The fix was to reorder napi_enable, napi_disable, request_irq and
free_irq calls, move register_netdev after dma_coerce_mask_and_coherent.
Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Tested-by: Khuong Dinh <kdinh@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>