make sock_alloc_file() do sock_release() on failures

make sock_alloc_file() do sock_release() on failures

This changes calling conventions (and simplifies the hell out
the callers).  New rules: once struct socket had been passed
to sock_alloc_file(), it's been consumed either by struct file
or by sock_release() done by sock_alloc_file().  Either way
the caller should not do sock_release() after that point.

Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Al Viro <[email protected]>
Signed-off-by: David S. Miller <[email protected]>