net: Always initialize struct sockaddr_storage.

net: Always initialize struct sockaddr_storage.

The static analyzer of clang claims that the left operand of the condition

	ss->ss_family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(&ia6->sin6_addr);

in SS_IS_ADDR_V4MAPPED() is a garbage value. The code has been like
this for seven years without problems, so the warning is probably
bogus.

It does not hurt to initialize the sockaddr_storage structures though,
which silences the warning.