if no shell given, chroot assumes /bin/bash, should use /bin/sh instead

[Baerbeisser]

I ran into this while chrooting into Adelie linux.
Using chroot /mnt, the error message was

chroot: failed to run command '/bin/bash': No such file or directory

Adelie has no bash by default. Of course, this was fixed with chroot /mnt /bin/sh. But /bin/sh is the closest we have to a standard and thus i think this should be used if no shell/tool is given.