use LIBS instead of LDADD

LDADD adds a dependence in Makefile rules which fails if the LDADD string contains special character sequences such as '-l'

tests/Makefile.am

@@ -28,7 +28,7 @@ endif
 
 AM_CFLAGS = $(HWLOC_CFLAGS) $(FXT_CFLAGS) -Wall $(STARPU_CUDA_CPPFLAGS) $(STARPU_OPENCL_CPPFLAGS) $(STARPU_COI_CPPFLAGS) $(STARPU_SCIF_CPPFLAGS) $(GLOBAL_AM_CFLAGS) -Wno-unused
 AM_CXXFLAGS = $(HWLOC_CFLAGS) $(FXT_CFLAGS) -Wall $(STARPU_CUDA_CPPFLAGS) $(STARPU_OPENCL_CPPFLAGS) $(STARPU_COI_CPPFLAGS) $(STARPU_SCIF_CPPFLAGS) $(GLOBAL_AM_CXXFLAGS) -Wno-unused
-LDADD = $(top_builddir)/src/@LIBSTARPU_LINK@ $(HWLOC_LIBS) $(FXT_LIBS)
+LIBS = $(top_builddir)/src/@LIBSTARPU_LINK@ $(HWLOC_LIBS) $(FXT_LIBS)
 AM_CPPFLAGS = -I$(top_srcdir)/include/ -I$(top_builddir)/src -I$(top_srcdir)/src/
 AM_LDFLAGS = @STARPU_EXPORT_DYNAMIC@ $(STARPU_OPENCL_LDFLAGS) $(STARPU_CUDA_LDFLAGS) $(STARPU_COI_LDFLAGS) $(STARPU_SCIF_LDFLAGS) $(FXT_LDFLAGS)