tools/testing/selftests/vm/hmm-tests.c: fix build

hmm-tests.c:1607:42: error: 'HMM_DMIRROR_MIGRATE' undeclared (first use in this function); did you mean 'HMM_DMIRROR_WRITE'?

Fixes: f6c3e1a ("mm/hmm: add a test for cross device private faults")
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Cc: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

tools/testing/selftests/vm/hmm-tests.c

@@ -1604,7 +1604,7 @@ TEST_F(hmm2, double_map)
 		ASSERT_EQ(ptr[i], i);
 
 	/* Migrate pages to device 1 and try to read from device 0. */
-	ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer, npages);
+	ret = hmm_migrate_sys_to_dev(self->fd1, buffer, npages);
 	ASSERT_EQ(ret, 0);
 	ASSERT_EQ(buffer->cpages, npages);