On the current error path of build_guest_fsinfo(), a non existent handle
is passed to CloseHandle().

This patch adds initialization of hLocalDiskHandle to
INVALID_HANDLE_VALUE, and checks for handle validity before the handle
is closed.

Signed-off-by: Basil Salman <basil@daynix.com>
Signed-off-by: Basil Salman <basil@redhat.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>