sockets: fix compilation on illumos

introduced in f3526e5

    sockets/unix_socket_nolinux.go:19:20: undefined: syscall.SysctlUint32
    sockets/unix_socket_nolinux.go:21:20: undefined: syscall.SysctlUint32
    sockets/unix_socket_nolinux.go:25:20: undefined: syscall.SysctlUint32

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

sockets/unix_socket_nolinux.go sockets/unix_socket_bsd.gosockets/unix_socket_nolinux.go renamed to sockets/unix_socket_bsd.go

@@ -1,4 +1,4 @@
-//go:build !linux && !windows
+//go:build darwin || dragonfly || freebsd || netbsd || openbsd
 
 package sockets
 

sockets/unix_socket_other.go

@@ -0,0 +1,9 @@
+//go:build !linux && !darwin && !dragonfly && !freebsd && !netbsd && !openbsd && !windows
+
+package sockets
+
+import "syscall"
+
+func maxListenerBacklog() int {
+	return syscall.SOMAXCONN
+}