setup: split off a function to handle hitting ceiling in repo search
setup: split off a function to handle hitting ceiling in repo search

Perhaps some day, other similar conditions (hitting the mount point,
hitting the root of the file system) will share this code.

Signed-off-by: Jonathan Nieder <b57189c5f2fd5b3daf3350a77fde90def1080fa5@gmail.com>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git