enic: initialize enic->rfs_h.lock in enic_probe

lockdep spotted that we are using rfs_h.lock in enic_get_rxnfc() without
initializing. rfs_h.lock is initialized in enic_open(). But ethtool_ops
can be called when interface is down.

Move enic_rfs_flw_tbl_init to enic_probe.

INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 18 PID: 1189 Comm: ethtool Not tainted 4.17.0-rc7-devel+ #27
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014
Call Trace:
dump_stack+0x85/0xc0
register_lock_class+0x550/0x560
? __handle_mm_fault+0xa8b/0x1100
__lock_acquire+0x81/0x670
lock_acquire+0xb9/0x1e0
?  enic_get_rxnfc+0x139/0x2b0 [enic]
_raw_spin_lock_bh+0x38/0x80
? enic_get_rxnfc+0x139/0x2b0 [enic]
enic_get_rxnfc+0x139/0x2b0 [enic]
ethtool_get_rxnfc+0x8d/0x1c0
dev_ethtool+0x16c8/0x2400
? __mutex_lock+0x64d/0xa00
? dev_load+0x6a/0x150
dev_ioctl+0x253/0x4b0
sock_do_ioctl+0x9a/0x130
sock_ioctl+0x1af/0x350
do_vfs_ioctl+0x8e/0x670
? syscall_trace_enter+0x1e2/0x380
ksys_ioctl+0x60/0x90
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x5a/0x170
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Signed-off-by: Govindarajulu Varadarajan <gvaradar@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>