net: phy: spi_ks8995: Introduce the use of devm_kzalloc

This patch introduces the use of devm_kzalloc and does away with the
kfrees in the probe and remove functions. Also, a label is removed.

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>