hush: output bash-compat killing signal names

This significantly syncronises ash-signals and hush-signals tests.

function                                             old     new   delta
process_wait_result                                  449     450      +1

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/hush_test/hush-signals/signal_read2.right b/shell/hush_test/hush-signals/signal_read2.right
index 71a6bc1..87d8da3 100644
--- a/shell/hush_test/hush-signals/signal_read2.right
+++ b/shell/hush_test/hush-signals/signal_read2.right
@@ -1,2 +1,2 @@
-HUP
+Hangup
 Done:129