i40e: Fix for unused value issue found by static analysis

This patch fixes an issue where an error return value is
set, but without an immediate exit, the value can be overwritten
by the following code execution.  The condition  at this point
is not fatal, so remove the error assignment and comment the
intent for future code maintainers

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>