net: dsa: mt7530: get rid of function sanity check

Get rid of checking whether functions are filled properly. priv->info which
is an mt753x_info structure is filled and checked for before this check.
It's unnecessary checking whether it's filled properly.

Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Signed-off-by: David S. Miller <davem@davemloft.net>