hv_sock: Suppress bogus "may be used uninitialized" warnings

hv_sock: Suppress bogus "may be used uninitialized" warnings

gcc 8.2.0 may report these bogus warnings under some condition:

warning: ‘vnew’ may be used uninitialized in this function
warning: ‘hvs_new’ may be used uninitialized in this function

Actually, the 2 pointers are only initialized and used if the variable
"conn_from_host" is true. The code is not buggy here.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>