testsuite: Add basic tests for hash implementation

Far from complete, but already covers all internal APIs.
diff --git a/Makefile.am b/Makefile.am
index 305d48e..14ddcab 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -247,7 +247,8 @@
 testsuite_libtestsuite_la_CPPFLAGS = $(TESTSUITE_CPPFLAGS)
 testsuite_libtestsuite_la_LIBADD = -lrt
 
-TESTSUITE = testsuite/test-init testsuite/test-testsuite testsuite/test-loaded \
+TESTSUITE = testsuite/test-hash \
+            testsuite/test-init testsuite/test-testsuite testsuite/test-loaded \
 	    testsuite/test-modinfo testsuite/test-util testsuite/test-new-module \
 	    testsuite/test-modprobe testsuite/test-blacklist \
 	    testsuite/test-dependencies testsuite/test-depmod
@@ -257,6 +258,10 @@
 
 testsuite_test_testsuite_LDADD = testsuite/libtestsuite.la libkmod/libkmod-util.la
 testsuite_test_testsuite_CPPFLAGS = $(TESTSUITE_CPPFLAGS)
+
+testsuite_test_hash_LDADD = $(TESTSUITE_LDADD)
+testsuite_test_hash_CPPFLAGS = $(TESTSUITE_CPPFLAGS)
+
 testsuite_test_init_LDADD = $(TESTSUITE_LDADD)
 testsuite_test_init_CPPFLAGS = $(TESTSUITE_CPPFLAGS)
 testsuite_test_loaded_LDADD = $(TESTSUITE_LDADD)