testsuite: add tests to modprobe --show-depends

test 1 - check whether modprobe outputs the right thing when
using --show-depends is used with already loaded modules.

test 2 - check whether modprobe outputs the right thing when
using --show-depends with modules not loaded yet
diff --git a/Makefile.am b/Makefile.am
index c3eb225..e847c5d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -173,7 +173,8 @@
 testsuite_libtestsuite_la_CPPFLAGS = $(TESTSUITE_CPPFLAGS)
 
 TESTSUITE = testsuite/test-init testsuite/test-testsuite testsuite/test-loaded \
-	    testsuite/test-modinfo testsuite/test-alias testsuite/test-new-module
+	    testsuite/test-modinfo testsuite/test-alias testsuite/test-new-module \
+	    testsuite/test-modprobe
 check_PROGRAMS = $(TESTSUITE)
 TESTS = $(TESTSUITE)
 
@@ -189,6 +190,8 @@
 testsuite_test_alias_CPPFLAGS = $(TESTSUITE_CPPFLAGS)
 testsuite_test_new_module_LDADD = $(TESTSUITE_LDADD)
 testsuite_test_new_module_CPPFLAGS = $(TESTSUITE_CPPFLAGS)
+testsuite_test_modprobe_LDADD = $(TESTSUITE_LDADD)
+testsuite_test_modprobe_CPPFLAGS = $(TESTSUITE_CPPFLAGS)
 
 DISTCHECK_CONFIGURE_FLAGS=--enable-gtk-doc