Add check_open(sock) to _sockname (JuliaLang#41000)

Not checking could lead to a segfault on closed TCPSockets in getpeername

Fixes JuliaLang#40993

Author: cljord

stdlib/Sockets/src/Sockets.jl

@@ -806,6 +806,7 @@ socket is connected to. Valid only for connected TCP sockets.
 getpeername(sock::TCPSocket) = _sockname(sock, false)
 
 function _sockname(sock, self=true)
+    sock.status == StatusInit || check_open(sock)
     rport = Ref{Cushort}(0)
     raddress = zeros(UInt8, 16)
     rfamily = Ref{Cuint}(0)