Use LOCALSTATEDIR for logfile location

Now that we have autoconf giving us installation directories, set the
log directory accordingly.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
diff --git a/Makefile.am b/Makefile.am
index 490e783..3d0a9b0 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -5,6 +5,8 @@
 
 AM_CFLAGS = -Wall -Wextra -Werror
 
+console_server_CPPFLAGS = -DLOCALSTATEDIR=\"$(localstatedir)\"
+
 console_server_SOURCES = \
 	 console-server.c \
 	 console-server.h \