[patch] missing xcalloc conversion

[Paul Brook]

The patch below replaces a use of xcalloc with xzalloc. Probably missed the 
first time round because it's only used on nommu targets.

Paul

Index: libbb/vfork_daemon_rexec.c
===================================================================
--- libbb/vfork_daemon_rexec.c	(revision 17075)
+++ libbb/vfork_daemon_rexec.c	(working copy)
@@ -43,7 +43,7 @@ void vfork_daemon_rexec(int nochdir, int
 			close(fd);
 	}
 
-	vfork_args = xcalloc(sizeof(char *), argc + 3);
+	vfork_args = xzalloc(sizeof(char *) * (argc + 3));
 	vfork_args[a++] = CONFIG_BUSYBOX_EXEC_PATH;
 	while(*argv) {
 		vfork_args[a++] = *argv;