kunmap_atomic() will call kpte_clear_flush with vaddr/ptep arguments
which don't correspond if the vaddr is just a normal lowmem address
(ie, not in the KMAP area). This patch makes sure that the pte is
only cleared if kmap area was actually used for the mapping.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xxxxxxxxxxxxx>
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: Zachary Amsden <zach@xxxxxxxxxx>