tools/testing/nvdimm: fix allocation range for mock flush hint tables

Commit 480b683 "nvdimm: fix PHYS_PFN/PFN_PHYS mixup" identified
that we were passing an invalid address to devm_nvdimm_ioremap(). With
that fixed it exposed a bug in the memory reservation size for flush
hint tables.  Since we map a full page we need to mock a full page of
memory to back the flush hint table entries.

Cc: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

tools/testing/nvdimm/test/nfit.c

@@ -603,7 +603,8 @@ static int nfit_test0_alloc(struct nfit_test *t)
  return -ENOMEM;
  sprintf(t->label[i], "label%d", i);
 
- t->flush[i] = test_alloc(t, sizeof(u64) * NUM_HINTS,
+ t->flush[i] = test_alloc(t, max(PAGE_SIZE,
+ sizeof(u64) * NUM_HINTS),
  &t->flush_dma[i]);
  if (!t->flush[i])
  return -ENOMEM;