ANDROID: KVM: arm64: Reset the parser state before dumping descriptors

The seq_file show function may be called multiple times if the space
of the seq_file buffer is not enough. Each time the show function is
called we need to reset the internal state of the ptdump parser before
we walk the descriptors.

Bug: 260238318
Bug: 278749606
Change-Id: I8b23df466c9252167d17bfb75527d1c64f9bff41
Signed-off-by: Sebastian Ene <sebastianene@google.com>