i40e: Fix potential out of bound array access

This is a fix for the static code analysis issue where dcbcfg->numapps
could be greater than size of array (i.e dcbcfg->app[I40E_DCBX_MAX_APPS]).
The fix makes sure that the array is not accessed past the size of
of the array (i.e. I40E_DCBX_MAX_APPS).

Copyright updated to 2017.

Signed-off-by: Sudheer Mogilappagari <sudheer.mogilappagari@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>