f2fs: remove false alarm on iget failure during GC

This patch removes setting SBI_NEED_FSCK when GC gets an error on f2fs_iget,
since f2fs_iget can give ENOMEM and others by race condition.
If we set this critical fsck flag, we'll get EIO during fsync via the below
code path.

In f2fs_inplace_write_data(),

	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK) || f2fs_cp_error(sbi)) {
		err = -EIO;
		goto drop_bio;
	}

Fixes: 95577278 ("f2fs: drop inplace IO if fs status is abnormal")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>