ARROW-15709: [C++] Compilation of ARROW_ENGINE fails if doing an "inline" build
ARROW-15709: [C++] Compilation of ARROW_ENGINE fails if doing an "inline" build

This change modifies the destination directory of the clone so it is unique.

Closes #12444 from westonpace/bugfix/ARROW-15709--substrait-clobbers-inline-build

Authored-by: Weston Pace <0dd0706858a011bb30a3fd82b71cee4f9094c502@gmail.com>
Signed-off-by: Weston Pace <0dd0706858a011bb30a3fd82b71cee4f9094c502@gmail.com>

icexelloss/arrow,icexelloss/arrow,apache/arrow,wesm/arrow,apache/arrow,kou/arrow,apache/arrow,kou/arrow,kou/arrow,icexelloss/arrow,wesm/arrow,kou/arrow,apache/arrow,apache/arrow,icexelloss/arrow,kou/arrow,icexelloss/arrow,wesm/arrow,kou/arrow,kou/arrow,wesm/arrow,kou/arrow,wesm/arrow,kou/arrow,apache/arrow,apache/arrow,apache/arrow,icexelloss/arrow,wesm/arrow,kou/arrow,apache/arrow,icexelloss/arrow,icexelloss/arrow,wesm/arrow,icexelloss/arrow,apache/arrow,wesm/arrow,wesm/arrow,apache/arrow,wesm/arrow,apache/arrow,kou/arrow,wesm/arrow,icexelloss/arrow,kou/arrow,wesm/arrow,kou/arrow,wesm/arrow,icexelloss/arrow,apache/arrow,icexelloss/arrow,kou/arrow,icexelloss/arrow,wesm/arrow,apache/arrow,icexelloss/arrow