The commit referenced below skipped pinning ram device memory when
ram blocks are added, we need to do the same when they're removed.

Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Fixes: cedc0ad5 ("target/i386: sev: Do not pin the ram device memory region")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Message-Id: <156320087103.2556.10983987500488190423.stgit@gimli.home>
Reviewed-by: Singh, Brijesh <brijesh.singh@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>