x86/bug: Handle __WARN_printf() trap in early_fixup_exception()

x86/bug: Handle __WARN_printf() trap in early_fixup_exception()

The commit 5b472b6e5bd9 ("x86_64/bug: Implement __WARN_printf()")
implemented __WARN_printf(), which changed the mechanism to use UD1
instead of UD2. However, it only handles the trap in the runtime IDT
handler, while the early booting IDT handler lacks this handling. As a
result, the usage of WARN() before the runtime IDT setup can lead to
kernel crashes. Since KMSAN is enabled after the runtime IDT setup, it
is safe to use handle_bug() directly in early_fixup_exception() to
address this issue.

Fixes: 5b472b6e5bd9 ("x86_64/bug: Implement __WARN_printf()")
Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/c4fb3645f60d3a78629d9870e8fcc8535281c24f.1768016713.git.houwenlong.hwl@antgroup.com