scripts/mod/modpost.c: fix commentary accordingly to last changes

The last commits
 37ed19d5cce35a40d3913cf9aa208ce9f60db3d7
 5003bab82d56754b27be01eef24495a02e00039d
have introduced new behaviour of sec2annotation() method. However, the
commentary inside the method was left as before. Let's fix it accordingly.

Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>