builtin/help.c: use warning_errno()

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/help.c

@@ -127,7 +127,7 @@ static void exec_woman_emacs(const char *path, const char *page)
 			path = "emacsclient";
 		strbuf_addf(&man_page, "(woman \"%s\")", page);
 		execlp(path, "emacsclient", "-e", man_page.buf, (char *)NULL);
-		warning(_("failed to exec '%s': %s"), path, strerror(errno));
+		warning_errno(_("failed to exec '%s'"), path);
 	}
 }
 
@@ -148,7 +148,7 @@ static void exec_man_konqueror(const char *path, const char *page)
 			path = "kfmclient";
 		strbuf_addf(&man_page, "man:%s(1)", page);
 		execlp(path, filename, "newTab", man_page.buf, (char *)NULL);
-		warning(_("failed to exec '%s': %s"), path, strerror(errno));
+		warning_errno(_("failed to exec '%s'"), path);
 	}
 }
 
@@ -157,7 +157,7 @@ static void exec_man_man(const char *path, const char *page)
 	if (!path)
 		path = "man";
 	execlp(path, "man", page, (char *)NULL);
-	warning(_("failed to exec '%s': %s"), path, strerror(errno));
+	warning_errno(_("failed to exec '%s'"), path);
 }
 
 static void exec_man_cmd(const char *cmd, const char *page)
@@ -165,7 +165,7 @@ static void exec_man_cmd(const char *cmd, const char *page)
 	struct strbuf shell_cmd = STRBUF_INIT;
 	strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 	execl(SHELL_PATH, SHELL_PATH, "-c", shell_cmd.buf, (char *)NULL);
-	warning(_("failed to exec '%s': %s"), cmd, strerror(errno));
+	warning(_("failed to exec '%s'"), cmd);
 }
 
 static void add_man_viewer(const char *name)