i40e: trivial: fix missing space

Missing space in comment, fixed.

Change-ID: I8cdf3ce5994b4a97dcc3eeb33422533918546667
Reported-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>