Just stub this cruft for crappy arches

http://bugs.gentoo.org/190613

--- schedutils/ionice.c
+++ schedutils/ionice.c
@@ -39,7 +39,8 @@
 #  define __NR_ioprio_set		196
 #  define __NR_ioprio_get		218
 # else
-#  error "Unsupported arch"
+#  define __NR_ioprio_set		-1
+#  define __NR_ioprio_get		-1
 # endif
 
 # define SYS_ioprio_get		__NR_ioprio_get