help: release strbuf on error return in exec_woman_emacs()

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/help.c

@@ -131,6 +131,7 @@ static void exec_woman_emacs(const char *path, const char *page)
 		strbuf_addf(&man_page, "(woman \"%s\")", page);
 		execlp(path, "emacsclient", "-e", man_page.buf, (char *)NULL);
 		warning_errno(_("failed to exec '%s'"), path);
+		strbuf_release(&man_page);
 	}
 }