efreet: Fix leak

When doing efreet_desktop_command_append_multiple we add all files from
command, whilst still looping command->files. So the command was created
with all files for all files.

Set l to NULL, since we parse all elements in command->files in
efreet_desktop_command_append_multiple to break the loop.

src/lib/efreet/efreet_desktop_command.c

@@ -381,6 +381,9 @@ efreet_desktop_command_build(Efreet_Desktop_Command *command)
                                     &len, command, *p);
                             if (!exec) goto error;
                             file_added = 1;
+                            /* Set l to NULL to break the loop, since we parse all command->files
+                             * in efreet_desktop_command_append_multiple */
+                            l = NULL;
                         }
                         break;
                     case 'i':