scsi: bnx2fc: Fix skb double free in bnx2fc_rcv()

scsi: bnx2fc: Fix skb double free in bnx2fc_rcv()

skb_share_check() already drops the reference to the skb when returning
NULL. Using kfree_skb() in the error handling path leads to an skb double
free.

Fix this by removing the variable tmp_skb, and return directly when
skb_share_check() returns NULL.

Fixes: 01a4cc4d0cd6 ("bnx2fc: do not add shared skbs to the fcoe_rx_list")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20221114110626.526643-1-weiyongjun@huaweicloud.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>