ade: Ensure the sample app code is dropped and checked out again

The current code fails because it tries to check out the sample app code twice
in the same place, and git complains.

Ensure that the repository is deleted between runs to avoid the issue.
Signed-off-by: Emanuele Aina <emanuele.aina@collabora.com>

ade/ade-tests-custom.sh

@@ -65,4 +65,4 @@ ade export
 
 ls -l *.bundle
 
-git clean -fdx
+rm -r ../sample-app

ade/ade-tests-defaults.sh

@@ -56,3 +56,5 @@ ade configure --debug --sysroot $DISTRIBUTION-$RELEASE-armhf
 ade export
 
 ls -l *.bundle
+
+rm -r ../sample-app