igb: Free any held skb that should have been timestamped on remove
igb: Free any held skb that should have been timestamped on remove

To prevent a race condition where an skb has been saved to return the Tx
timestamp later and the driver is removed, add a check to determine if we
have an skb stored and, if so, free it.

Cc: Richard Cochran <e27030aebe9cad8817d34b8c31dbaf301fb798b9@gmail.com>
Signed-off-by: Matthew Vick <d265f499ad1500ed47610cc699ddce50365eb4ad@intel.com>
Acked-by: Jacob Keller <fabc09ab02be50b7572cb9bdf511a191941adf10@intel.com>
Tested-by: Aaron Brown <4723df1d9a4136f7b76e1bf6434e33afc91d2139@intel.com>
Signed-off-by: Jeff Kirsher <87e35f5be20bb3e67f4ba6b86f5f6be3085b1b3a@intel.com>

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas