Consider the following scenario: 2 HCAs, where only one of which can run SRIOV.

If we reset the module parameter, all the VFs of the SRIOV HCA will be
claimed by the PPF host (-- the code relies on num_vfs being non-zero
to avoid this claiming, and num_vfs was reset when pci_enable_sriov failed
for the non-SRIOV HCA).

The solution is not to touch the num_vfs parameter.

Also, eliminate the unneeded check of num_vfs when disabling sriov
(the dev flag bit is sufficient).
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>