examples/var_service: use "exec sleep 5" instead of "{ sleep 5; exit; }"

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/examples/var_service/dhcp_if/run b/examples/var_service/dhcp_if/run
index d8f3435..882f008 100755
--- a/examples/var_service/dhcp_if/run
+++ b/examples/var_service/dhcp_if/run
@@ -8,7 +8,7 @@
 if="${PWD##*/dhcp_}"
 
 echo "* Upping iface $if"
-ip link set dev "$if" up || { sleep 5; exit; }
+ip link set dev "$if" up || exec sleep 5
 
 echo "* Starting udhcpc on $if [$$]"
 exec \