Consistenly format variables in */Makefile.am files

Change-Id: Ifa21513c007072314097b7bec188579972dc1694
diff --git a/openbsc/tests/trau/Makefile.am b/openbsc/tests/trau/Makefile.am
index cc1b4ef..93ce88e 100644
--- a/openbsc/tests/trau/Makefile.am
+++ b/openbsc/tests/trau/Makefile.am
@@ -1,17 +1,46 @@
-AM_CPPFLAGS = $(all_includes) -I$(top_srcdir)/include
-AM_CFLAGS=-Wall -ggdb3 $(LIBOSMOCORE_CFLAGS) $(LIBOSMOGSM_CFLAGS) $(LIBOSMOABIS_CFLAGS) $(LIBSMPP34_CFLAGS) $(COVERAGE_CFLAGS)
-AM_LDFLAGS = $(COVERAGE_LDFLAGS)
+AM_CPPFLAGS = \
+	$(all_includes) \
+	-I$(top_srcdir)/include \
+	$(NULL)
 
-EXTRA_DIST = trau_test.ok
+AM_CFLAGS = \
+	-Wall \
+	-ggdb3 \
+	$(LIBOSMOCORE_CFLAGS) \
+	$(LIBOSMOGSM_CFLAGS) \
+	$(LIBOSMOABIS_CFLAGS) \
+	$(LIBSMPP34_CFLAGS) \
+	$(COVERAGE_CFLAGS) \
+	$(NULL)
 
-noinst_PROGRAMS = trau_test
+AM_LDFLAGS = \
+	$(COVERAGE_LDFLAGS) \
+	$(NULL)
 
-trau_test_SOURCES = trau_test.c
-trau_test_LDADD = $(top_builddir)/src/libbsc/libbsc.a \
-		$(top_builddir)/src/libmsc/libmsc.a \
-		$(top_builddir)/src/libbsc/libbsc.a \
-		$(top_builddir)/src/libtrau/libtrau.a \
-		$(top_builddir)/src/libcommon/libcommon.a \
-		$(LIBOSMOCORE_LIBS) $(LIBOSMOABIS_LIBS) \
-		$(LIBOSMOGSM_LIBS) $(LIBSMPP34_LIBS) $(LIBOSMOVTY_LIBS) $(LIBRARY_DL) -ldbi
+EXTRA_DIST = \
+	trau_test.ok \
+	$(NULL)
+
+noinst_PROGRAMS = \
+	trau_test \
+	$(NULL)
+
+trau_test_SOURCES = \
+	trau_test.c \
+	$(NULL)
+
+trau_test_LDADD = \
+	$(top_builddir)/src/libbsc/libbsc.a \
+	$(top_builddir)/src/libmsc/libmsc.a \
+	$(top_builddir)/src/libbsc/libbsc.a \
+	$(top_builddir)/src/libtrau/libtrau.a \
+	$(top_builddir)/src/libcommon/libcommon.a \
+	$(LIBOSMOCORE_LIBS) \
+	$(LIBOSMOABIS_LIBS) \
+	$(LIBOSMOGSM_LIBS) \
+	$(LIBSMPP34_LIBS) \
+	$(LIBOSMOVTY_LIBS) \
+	$(LIBRARY_DL) \
+	-ldbi \
+	$(NULL)