Extend the interface name length to allow any UDS address.

This patch increases the maximum length of an interface name to
accommodate a UNIX domain socket address of 108 bytes. (This value is
hard coded in the glibc headers, and so we cannot use the Linux kernel
header macro, UNIX_PATH_MAX.)

Signed-off-by: Richard Cochran <richardcochran@gmail.com>

config.h

@@ -27,7 +27,7 @@
 #include "sk.h"
 
 #define MAX_PORTS 8
-#define MAX_IFNAME_SIZE 16
+#define MAX_IFNAME_SIZE 108 /* = UNIX_PATH_MAX */
 
 /** Defines a network interface, with PTP options. */
 struct interface {