Use a different variable when referring to the json.la file, since the original lib_LTLIBRARIES means something special to automake.

tests/Makefile.am

@@ -1,23 +1,23 @@
 
 include ../Makefile.am.inc
 
-lib_LTLIBRARIES = $(top_builddir)/libjson.la
+LIBJSON_LA=$(top_builddir)/libjson.la
 
 check_PROGRAMS = test1 test2 test4 test_parse_int64 test_null test_cast test_parse
 
-test1_LDADD = $(lib_LTLIBRARIES)
+test1_LDADD = $(LIBJSON_LA)
 
-test2_LDADD = $(lib_LTLIBRARIES)
+test2_LDADD = $(LIBJSON_LA)
 
-test4_LDADD = $(lib_LTLIBRARIES)
+test4_LDADD = $(LIBJSON_LA)
 
-test_parse_int64_LDADD = $(lib_LTLIBRARIES)
+test_parse_int64_LDADD = $(LIBJSON_LA)
 
-test_null_LDADD = $(lib_LTLIBRARIES)
+test_null_LDADD = $(LIBJSON_LA)
 
-test_cast_LDADD = $(lib_LTLIBRARIES)
+test_cast_LDADD = $(LIBJSON_LA)
 
-test_parse_LDADD = $(lib_LTLIBRARIES)
+test_parse_LDADD = $(LIBJSON_LA)
 
 TESTS = test1.test test2.test test4.test parse_int64.test test_null.test test_cast.test test_parse.test
 EXTRA_DIST=