[PATCH] ppc64: Check of_chosen in check_for_initrd()

You can't call get_property() on a NULL node, so check if of_chosen is set
in check_for_initrd().

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
 arch/ppc64/kernel/setup.c |   20 ++++++++++++--------
 1 files changed, 12 insertions(+), 8 deletions(-)
Signed-off-by: Paul Mackerras <paulus@samba.org>