Cleanup library makefile

Signed-off-by: Chris Michael <devilhorns@comcast.net>

src/lib/Makefile.am

@@ -5,11 +5,10 @@ AM_CPPFLAGS = \
   -I$(top_srcdir)/src/lib \
   -I$(top_builddir)/src/lib \
   -DPACKAGE_LOCALE_DIR=\"$(datadir)/locale\" \
+  -DPACKAGE_LIB_DIR=\"$(libdir)\" \
   -DUSE_EXPRESS_CONFIG_H \
   @LIBEXPRESS_CFLAGS@
 
-AM_CPPFLAGS=-DPACKAGE_LIB_DIR=\"$(libdir)\"
-
 pkgdir = $(libdir)
 pkg_LTLIBRARIES = libexpress.la