i40e: Disable VEB bridge mode with SR-IOV failure

If a call to enable SR-IOV in the kernel failed, we need to disable
I40E_FLAG_VEB_MODE_ENABLED, so that bridge mode could fall back to
VEPA, which is a default.

Change-ID: I12b6f776769506db85b29bea94b9c88d0b5ee65e
Signed-off-by: Akeem G Abodunrin <akeem.g.abodunrin@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>