[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>

arch/ppc64/kernel/setup.c

@@ -536,16 +536,20 @@ static void __init check_for_initrd(void)
 
 	DBG(" -> check_for_initrd()\n");
 
-	prop = (u64 *)get_property(of_chosen, "linux,initrd-start", NULL);
+	if (of_chosen) {
+		prop = (u64 *)get_property(of_chosen,
+				"linux,initrd-start", NULL);
 		if (prop != NULL) {
 			initrd_start = (unsigned long)__va(*prop);
-		prop = (u64 *)get_property(of_chosen, "linux,initrd-end", NULL);
+			prop = (u64 *)get_property(of_chosen,
+					"linux,initrd-end", NULL);
 			if (prop != NULL) {
 				initrd_end = (unsigned long)__va(*prop);
 				initrd_below_start_ok = 1;
 			} else
 				initrd_start = 0;
 		}
+	}
 
 	/* If we were passed an initrd, set the ROOT_DEV properly if the values
 	 * look sensible. If not, clear initrd reference.