net/netvsc: fix chimney buffer size error handling
net/netvsc: fix chimney buffer size error handling

Fix the error handling in setting up transmit buffer.
If setting up chimney buffer fails, then it is not connected so
no need to send disconnect.

Allow for some unused area if full area is not used.

Fixes: 4e9c73e96e83 ("net/netvsc: add Hyper-V network device")
Cc: stable@dpdk.org

Signed-off-by: Stephen Hemminger <6e2d829dccd9a999246d37fa28053b3b607441a0@microsoft.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk