socket: Actually use the console-socket definitions

Since the console_socket variables aren't declared with 'extern' in
console-server.h, we ended up with default definitions for these. This
happened to work, but with a zero-length socket path.

This change uses the console-socket.c object as intended, to provide
proper socket paths.

Now that the char[] is an extern, we'll need to get the address of it to
get the pointer value.

Also, fix the sizeof() to take account of the trailing nul.

Found by Joel Stanley <joel@jms.id.au>.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
diff --git a/console-socket.c b/console-socket.c
index 45095a3..9e1cf30 100644
--- a/console-socket.c
+++ b/console-socket.c
@@ -14,7 +14,9 @@
  * limitations under the License.
  */
 
-const char console_socket_path[] = "\0obmc-uart-console";
-const size_t console_socket_len = sizeof(console_socket_path);
+#include <sys/types.h>
+
+const char console_socket_path[] = "\0obmc-console";
+const size_t console_socket_path_len = sizeof(console_socket_path) - 1;
 const char *console_socket_path_readable = console_socket_path + 1;