Drivers: hv: kvp: Fix the recent regression caused by incorrect clean-up

In kvp_send_key(), we do need call process_ib_ipinfo() if
message->kvp_hdr.operation is KVP_OP_GET_IP_INFO, because it turns out
the userland hv_kvp_daemon needs the info of operation, adapter_id and
addr_family. With the incorrect fc62c3b1, the host can't get the
VM's IP via KVP.

And, fc62c3b1 added a "break;", but actually forgot to initialize
the key_size/value in the case of KVP_OP_SET, so the default key_size of
0 is passed to the kvp daemon, and the pool files
/var/lib/hyperv/.kvp_pool_* can't be updated.

This patch effectively rolls back the previous fc62c3b1, and
correctly fixes the "this statement may fall through" warnings.

This patch is tested on WS 2012 R2 and 2016.

Fixes: fc62c3b1 ("Drivers: hv: kvp: Fix two "this statement may fall through" warnings")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>