Revert "net: liquidio: fix a NULL pointer dereference"

Revert "net: liquidio: fix a NULL pointer dereference"

This reverts commit 35474b8c908ba36f4f235ecc991d75f34fd3848b.

Because of recent interactions with developers from @umn.edu, all
commits from them have been recently re-reviewed to ensure if they were
correct or not.

Upon review, this commit was found to be incorrect for the reasons
below, so it must be reverted.  It will be fixed up "correctly" in a
later kernel change.

While the original commit does keep the immediate "NULL dereference"
from happening, it does not properly propagate the error back to the
callers, AND it does not fix this same identical issue in the
drivers/net/ethernet/cavium/liquidio/lio_vf_main.c for some reason.

Cc: Kangjie Lu <kjlu@umn.edu>
Cc: David S. Miller <davem@davemloft.net>
Link: https://lore.kernel.org/r/20210503115736.2104747-65-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>