updated for version 7.3.742

Problem:    Leaking memory when :vimgrep restores the directory.
Solution:   Free the allocated memory. (Christian Brabandt)

src/quickfix.c

@@ -3515,6 +3515,7 @@ restore_start_dir(dirname_start)
 	    ea.cmdidx = (curwin->w_localdir == NULL) ? CMD_cd : CMD_lcd;
 	    ex_cd(&ea);
 	}
+	vim_free(dirname_now);
     }
 }