mm/debug_vm_pgtable: avoid none pte in pte_clear_test

pte_clear_tests operate on an existing pte entry.  Make sure that is not a
none pte entry.

[[email protected]: avoid kernel crash with riscv]
  Link: https://lkml.kernel.org/r/[email protected]

Signed-off-by: Aneesh Kumar K.V <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: Anshuman Khandual <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions