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/Makefile.am b/Makefile.am
index 1da5d35..5f0a1bb 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -33,11 +33,13 @@
 	 util.c \
 	 config.c \
 	 log-handler.c \
-	 socket-handler.c
+	 socket-handler.c \
+	 console-socket.c
 
 obmc_console_client_SOURCES = \
 	 console-client.c \
 	 console-server.h \
+	 console-socket.c \
 	 util.c
 
 config_test_CPPFLAGS = -DCONFIG_TEST -DSYSCONFDIR=\"\"