don't leave .elf files around in the tree.  (do we need to generate these
by default?)

- erik

Reference: /n/patches.lsub.org/patch/elfdroppings
Date: Thu Jun 21 09:23:57 CES 2012
Signed-off-by: quanstro@quanstro.net

# rm /sys/src/nix/k10/9k8cpu.elf

--- /sys/src/nix/mk/portmkfile	Thu Apr 12 12:26:28 2012
+++ /sys/src/nix/mk/portmkfile	Thu Jun 21 08:14:16 2012
@@ -113,7 +113,7 @@
 		mk 'CONF='$i install
 
 %.clean:V:
-	rm -f $stem.c [9bz]$stem [9bz]$stem.gz boot$stem.*
+	rm -f $stem.c [9bz]$stem 9$stem.elf [9bz]$stem.gz boot$stem.*
 
 clean:V:
 	rm -f *.[$OS] *.root.[cs] *.out *.m *.acid errstr.h init.h $objtype^l.h