ANDROID: KVM: Fix prefaulting when breaking PMD blocks

A wild typo appeared when porting the this function from Android15-6.6 to
Android16-6.12 where KVM_PGTABLE_MAX_LEVELS has been replaced with
KVM_PGTABLE_LAST_LEVEL. KVM_PGTABLE_LAST_LEVEL == KVM_PGTABLE_MAX_LEVELS
- 1.

Bug: 357781595
Bug: 278749606
Bug: 308373293
Fixes: a02ff909 ("ANDROID: KVM: arm64: Fix prefaulting when breaking PUD blocks")
Change-Id: I10c2cb1985eb7d18f8bd7c317839598759a6e438
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>