FROMGIT: f2fs: fix infinite loop in __insert_extent_tree()

When we get wrong extent info data, and look up extent_node in rb tree,
it will cause infinite loop (CONFIG_F2FS_CHECK_FS=n). Avoiding this by
return NULL and print some kernel messages in that case.

Signed-off-by: wangzijie <wangzijie1@honor.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Bug: 451000314
Bug: 445867857
Bug: 451765062
(cherry picked from commit 23361bd5
 https: //git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git dev)
Link: https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git/commit/?h=dev-test&id=23361bd54966b437e1ed3eb1a704572f4b279e58


Change-Id: Idfa7b478f874bad240896b410e91eb3b73ebaf95
Signed-off-by: Rui Chen <chenrui9@honor.com>
(cherry picked from commit c5148581)