ehea: Fix a DLPAR bug on ehea_rereg_mrs().

We are currently continuing if ehea_restart_qps() fails, when we
do a memory DLPAR (remove or add more memory to the system).

This patch just let the NAPI disabled if the ehea_restart_qps()
fails.

Signed-off-by: Breno Leitao <leitao@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>