powerpc: Fix setting of oprofile cpu type

commit 2657dd4e301d4841ed67a4fac7d145ad8f3e1b28 introduced a
bug where we would now always override the "real" oprofile CPU
type with the "compatible" one provided by a pseudo-PVR in the
device-tree which is incorrect and breaks oprofile on all current
configs since the "compatible" ones aren't yet recognized.

This fixes it.

Signed-off-by: Benjamin Herrenschmidt <[e-mail]>

arch/powerpc/kernel/cputable.c

···
 		 * oprofile_cpu_type.
 		 */
 		if (old.oprofile_cpu_type == NULL) {
-			t->oprofile_cpu_type = s->oprofile_cpu_type;
-			t->oprofile_type = s->oprofile_type;
+			t->oprofile_cpu_type = old.oprofile_cpu_type;
+			t->oprofile_type = old.oprofile_type;
 		}
 	}