replace and remove run_command_v_opt_cd_env()

run_command_v_opt_cd_env() is only used in an example in a comment.  Use
the struct child_process member "env" and run_command() directly instead
and then remove the unused convenience function.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
diff --git a/run-command.c b/run-command.c
index 5ec3a46..1c9ed51 100644
--- a/run-command.c
+++ b/run-command.c
@@ -1006,7 +1006,7 @@ int run_command(struct child_process *cmd)
 
 int run_command_v_opt(const char **argv, int opt)
 {
-	return run_command_v_opt_cd_env(argv, opt, NULL, NULL);
+	return run_command_v_opt_cd_env_tr2(argv, opt, NULL, NULL, NULL);
 }
 
 int run_command_v_opt_tr2(const char **argv, int opt, const char *tr2_class)
@@ -1014,11 +1014,6 @@ int run_command_v_opt_tr2(const char **argv, int opt, const char *tr2_class)
 	return run_command_v_opt_cd_env_tr2(argv, opt, NULL, NULL, tr2_class);
 }
 
-int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
-{
-	return run_command_v_opt_cd_env_tr2(argv, opt, dir, env, NULL);
-}
-
 int run_command_v_opt_cd_env_tr2(const char **argv, int opt, const char *dir,
 				 const char *const *env, const char *tr2_class)
 {
diff --git a/run-command.h b/run-command.h
index 61073fc..39e5eae 100644
--- a/run-command.h
+++ b/run-command.h
@@ -151,7 +151,7 @@ struct child_process {
 
 /**
  * The functions: start_command, finish_command, run_command,
- * run_command_v_opt, run_command_v_opt_cd_env do the following:
+ * run_command_v_opt do the following:
  *
  * - If a system call failed, errno is set and -1 is returned. A diagnostic
  *   is printed.
@@ -249,7 +249,6 @@ int run_command_v_opt_tr2(const char **argv, int opt, const char *tr2_class);
  * env (the environment) is to be formatted like environ: "VAR=VALUE".
  * To unset an environment variable use just "VAR".
  */
-int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env);
 int run_command_v_opt_cd_env_tr2(const char **argv, int opt, const char *dir,
 				 const char *const *env, const char *tr2_class);
 
diff --git a/tmp-objdir.h b/tmp-objdir.h
index 76efc7e..237d96b 100644
--- a/tmp-objdir.h
+++ b/tmp-objdir.h
@@ -10,9 +10,11 @@
  *
  * Example:
  *
+ *	struct child_process child = CHILD_PROCESS_INIT;
  *	struct tmp_objdir *t = tmp_objdir_create("incoming");
- *	if (!run_command_v_opt_cd_env(cmd, 0, NULL, tmp_objdir_env(t)) &&
- *	    !tmp_objdir_migrate(t))
+ *	strvec_push(&child.args, cmd);
+ *	strvec_pushv(&child.env, tmp_objdir_env(t));
+ *	if (!run_command(&child)) && !tmp_objdir_migrate(t))
  *		printf("success!\n");
  *	else
  *		die("failed...tmp_objdir will clean up for us");