[PATCH] erofs-utils: fix multiple definition of `sbi'

[nl6720]

On Tuesday, 8 December 2020 12:57:41 EET Gao Xiang wrote:
> As nl6720 reported [1], lib/inode.o (mkfs) and lib/super.o (erofsfuse)
> could be compiled together by some options. Fix it now.
> 
> [1] https://lore.kernel.org/r/10789285.Na0ui7I3VY@walnut
> Reported-by: nl6720 <nl6720 at gmail.com>
> Signed-off-by: Gao Xiang <hsiangkao at aol.com>
> ---
> Hi nl6720,
> could you verify this patch? Thanks in advance!
> 
> Thanks,
> Gao Xiang

This patch fixes the build issue for me. Thanks!