Fixing build with as-needed

https://bugs.gentoo.org/show_bug.cgi?id=248555

--- configure.in
+++ configure.in
@@ -47,14 +47,9 @@
 AC_PATH_X
 AC_PATH_XTRA
 
-CFLAGS="$CFLAGS $X_CFLAGS"
-CXXFLAGS="$CXXFLAGS $X_CFLAGS"
-LDFLAGS="$LDFLAGS $X_LIBS $X_PRE_LIBS"
 dnl Checks for X libraries.
-AC_CHECK_LIB(X11, XOpenDisplay, LDFLAGS="$LDFLAGS -lX11",
-             AC_MSG_ERROR(XOpenDisplay not found in -lX11))
-
-LDFLAGS="$LDFLAGS $X_EXTRA_LIBS"
+AC_CHECK_LIB([X11], [XOpenDisplay], ,
+             AC_MSG_ERROR(XOpenDisplay not found in -lX11),)
 
 dnl Checks for header files.
 AC_HEADER_STDC
--- Makefile.am
+++ Makefile.am
@@ -1,5 +1,4 @@
-CPPFLAGS =	@CPPFLAGS@ \
-		-DDEFAULT_CONF=\"$(datadir)/bbtools/bbtime.conf\" \
+AM_CPPFLAGS =	-DDEFAULT_CONF=\"$(datadir)/bbtools/bbtime.conf\" \
 		-DDEFAULT_NOBB=\"$(datadir)/bbtools/bbtime.nobb\"
 
 
@@ -14,4 +13,5 @@
 		 timemenu.cc timemenu.hh \
 		 blackboxstyle.hh
 EXTRA_DIST = BUGS TODO
-bbtime_LDADD = @X_LIBS@
+bbtime_LDADD = @X_PRE_LIBS@ @X_LIBS@ @X_EXTRA_LIBS@
+bbtime_CFLAGS = @X_PRE_CFLAGS@ @X_CGLAGS@ @X_EXTRA_CFLAGS@