tools/testing/nvdimm: force nfit_test to depend on instrumented modules

The libnvdimm unit tests will fail when they are run against the
production / in-tree version of libnvdimm.ko or nfit.ko due to
symbols not being mocked per nfit_test's expectation. For example,
nfit_test expects acpi_evaluate_dsm() to be replaced by
__wrap_acpi_evaluate_dsm() to test how acpi_nfit_ctl() responds to
different stimuli.

Create a test-only symbol name that nfit_test links against to cause
module load failures when the wrong module is present.

For example, with this change, attempts to use the wrong module will
report:

    nfit_test: Unknown symbol libnvdimm_test (err 0)

Reported-by: Dave Jiang <dave.jiang@intel.com>
Reported-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

tools/testing/nvdimm/test/nfit.c

@@ -27,6 +27,7 @@
 #include <nfit.h>
 #include <nd.h>
 #include "nfit_test.h"
+#include "../watermark.h"
 
 /*
  * Generate an NFIT table to describe the following topology:
@@ -2545,6 +2546,11 @@ static __init int nfit_test_init(void)
 {
 	int rc, i;
 
+	pmem_test();
+	libnvdimm_test();
+	acpi_nfit_test();
+	device_dax_test();
+
 	nfit_test_setup(nfit_test_lookup, nfit_test_evaluate_dsm);
 
 	nfit_wq = create_singlethread_workqueue("nfit");