ixgbe: Add error checking to setting VF MAC

Currently, when setting a VF MAC address there are no error checks to
ensure that the MAC filter was successfully added.  This patch adds
additional error checks, reporting, and propagation of errors.  It also
will not set the MAC address unless adding the MAC filter was successful.

With these changes, setting the mac address to zeros can no longer call
ixgbe_set_vf_mac() as adding a zero MAC address filter is not valid.
Instead directly delete the filter and, if successful, clear the MAC
address.

Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>