gcc-plugins: randstruct: Update code comment in relayout_struct()

stable inclusion
from stable-v6.6.7
commit b79210fa10db4cab09b19965f6cc47bc393e47e9
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8SSQ4

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b79210fa10db4cab09b19965f6cc47bc393e47e9



--------------------------------

commit d71f22365a9caca82d424f3a33445de46567e198 upstream.

Update code comment to clarify that the only element whose layout is
not randomized is a proper C99 flexible-array member. This update is
complementary to commit 1ee60356c2dc ("gcc-plugins: randstruct: Only
warn about true flexible arrays")

Signed-off-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/ZWJr2MWDjXLHE8ap@work


Fixes: 1ee60356c2dc ("gcc-plugins: randstruct: Only warn about true flexible arrays")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>