sstate: Run sstate_cleanall() as part of do_setscene()

Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

meta/classes/sstate.bbclass

@@ -187,6 +187,8 @@ def sstate_clean(ss, d):
     for lock in locks:
         bb.utils.unlockfile(lock)
 
+SCENEFUNCS += "sstate_cleanall"
+
 python sstate_cleanall() {
     import fnmatch