i40iw: Remove checks for more than 48 bytes inline data

Remove dead code, which isn't executed because we
return error if the data size is greater than 48 bytes.

Inline data size greater than 48 bytes isn't supported
and the maximum WQE size is 64 bytes.

Signed-off-by: Tatyana Nikolova <tatyana.e.nikolova@intel.com>
Signed-off-by: Henry Orosco <henry.orosco@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>