f2fs: clean up error handling in sanity_check_{compress_,}inode()

In sanity_check_{compress_,}inode(), it doesn't need to set SBI_NEED_FSCK
in each error case, instead, we can set the flag in do_read_inode() only
once when sanity_check_inode() fails.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>