net: fec: correct fix method about miss init spinlock

net: fec: correct fix method about miss init spinlock

Old method will cause init spinlock twice.
New method will avoid init spinlock twice and fix miss init spinlock
at fec_restart.

BUG: spinlock bad magic on CPU#1, swapper/0/1
lock: 0xbfae0f8c, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
Backtrace:
 [<80011d54>] (dump_backtrace+0x0/0x10c) from [<804e7800>] (dump_stack+0x18/0x1c)
 r6:bfae0000 r5:bfae0f8c r4:00000000 r3:806c1310
 [<804e77e8>] (dump_stack+0x0/0x1c) from [<804e9f20>] (spin_dump+0x80/0x94)
 [<804e9ea0>] (spin_dump+0x0/0x94) from [<804e9f60>] (spin_bug+0x2c/0x30)
 r5:805f6f8c r4:bfae0f8c
 [<804e9f34>] (spin_bug+0x0/0x30) from [<80257984>] (do_raw_spin_lock+0x170/0x1b0                                         )
 r5:806b4950 r4:bfae0f8c
 [<80257814>] (do_raw_spin_lock+0x0/0x1b0) from [<804ed15c>] (_raw_spin_lock_irqs                                         ave+0x18/0x20)
 [<804ed144>] (_raw_spin_lock_irqsave+0x0/0x20) from [<8033c694>] (fec_ptp_start_                                         cyclecounter+0x3c/0x120)
 r4:bfae0f8c r3:00000002
 [<8033c658>] (fec_ptp_start_cyclecounter+0x0/0x120) from [<80339e08>] (fec_resta                                         rt+0x56c/0x5f8)
 r8:00000000 r7:806e6f48 r6:00000112 r5:806b4950 r4:bfae0000
 [<8033989c>] (fec_restart+0x0/0x5f8) from [<8033b9e4>] (fec_probe+0x508/0xa48)

Signed-off-by: Frank Li <Frank.Li@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>