tests: use 'check_PROGRAMS' instead of 'noinst_PROGRAMS'

When using 'check_PROGRAMS', autoconf/automake generates smarter
Makefiles, so that the test programs are not being compiled during
the normal 'make all', but only during 'make check'.

Change-Id: I70cf75b3cb6ae59c92248cc529546750fb0da07b
diff --git a/tests/gsup/Makefile.am b/tests/gsup/Makefile.am
index 5dbb180..9a10597 100644
--- a/tests/gsup/Makefile.am
+++ b/tests/gsup/Makefile.am
@@ -17,7 +17,7 @@
 	gsup_test.err \
 	$(NULL)
 
-noinst_PROGRAMS = \
+check_PROGRAMS = \
 	gsup_test \
 	$(NULL)