qlcnic: Simplify DMA setting

qlcnic: Simplify DMA setting

As stated in [1], dma_set_mask() with a 64-bit mask will never fail if
dev->dma_mask is non-NULL.
So, if it fails, the 32 bits case will also fail for the same reason.

So qlcnic_set_dma_mask(), (in qlcnic_main.c) can be simplified a lot and
inlined directly in its only caller.

If dma_set_mask_and_coherent() succeeds, 'pci_using_dac' is known to be 1.
So it can be removed from all the calling chain.

qlcnic_setup_netdev() can finally be simplified as-well.

[1]: https://lkml.org/lkml/2021/6/7/398

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/4996ab0337d62ec6a54b2edf234cd5ced4b4d7ad.1641649611.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Jakub Kicinski <kuba@kernel.org>