[POWERPC] allocation fix in ppc/platforms/4xx/luan.c

Don't allocate hose2 when when hose1 can't be allocated and free hose1 when
hose2 can't be allocated.

Signed-off-by: Roel Kluin <12o3l@tiscali.nl>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>