*: code shrink and better "died from signal" reporting from wait4pid

function                                             old     new   delta
parse                                                964     967      +3
udhcp_run_script                                     670     665      -5
singlemount                                          911     906      -5
mount_it_now                                         360     355      -5
inotifyd_main                                        521     516      -5
xspawn                                                21       -     -21
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 1/4 up/down: 3/-41)             Total: -38 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/networking/udhcp/script.c b/networking/udhcp/script.c
index 574c74f..a74697c 100644
--- a/networking/udhcp/script.c
+++ b/networking/udhcp/script.c
@@ -271,7 +271,7 @@
 	argv[0] = (char*) client_config.script;
 	argv[1] = (char*) name;
 	argv[2] = NULL;
-	wait4pid(spawn(argv));
+	spawn_and_wait(argv);
 
 	for (curr = envp; *curr; curr++) {
 		log2(" %s", *curr);