igb: Fix a memory leak in igb_probe

igb: Fix a memory leak in igb_probe

In error handling code of igb_probe, the memory adapter->shadow_vfta
allocated by kcalloc in igb_sw_init is not freed. So when register_netdev
or igb_init_i2c is failed, a memory leak will occur.
This patch adds kfree to fix it.

Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit 42ad1a03b4caf4d95b980bce17c46242e6728ddc)

Orabug: 26325580

Signed-off-by: Kirtikar Kashyap <kirtikar.kashyap@oracle.com>
Reviewed-by: Jack Vogel <jack.vogel@oracle.com>