Revert "HOWTO: bug report addition" (or "HOWTO: mention bughunting")

This reverts commit 722385f7 (or commit
3f271008

, it's your choice ;), since the
same patch to Documentation/HOWTO got added twice because it just kept
applying cleanly.

Noted by Qi Yong.

Cc: Qi Yong <qiyong@fc-cn.com>
Acked-by: Diego Calleja <diegocg@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>