cxgb4: remove a bogus PCI function number check

Remove a bogus PCI function number check from the driver's .remove
method that causes pci_release_regions not to be called for function 0
if additional functions are attached and one of them is used as primary.

Signed-off-by: Dimitris Michailidis <dm@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>