Kernel: Support binding to INADDR_ANY (all IPs)

Author: https://github.com/deoxxa
Commit: 4fcbbd24f7
Pull-request: https://github.com/SerenityOS/serenity/pull/421
Reviewed-by: https://github.com/awesomekling ✅

Kernel/Net/IPv4Socket.cpp

@@ -95,9 +95,6 @@ KResult IPv4Socket::listen(int backlog)
     if (rc < 0)
         return KResult(-EADDRINUSE);
 
-    if (m_local_address.to_u32() == 0)
-        return KResult(-EADDRINUSE);
-
     set_backlog(backlog);
 
     kprintf("IPv4Socket{%p} listening with backlog=%d\n", this, backlog);