fix check-elf-dynamic-objects -p

It needs to wait for all background tasks to exit.

Change-Id: I8770f3d79d66ab2fae727ae7cbbc00e3b22e5e54

bin/check-elf-dynamic-objects

@@ -188,6 +188,8 @@ else
 	)>> check_elf.out &
     done
 
+    for file in ${files}; do wait; done
+
     if [ -s check_elf.out ] ; then
 	cat check_elf.out
 	status=1