Upload folder is missing, leading to test failures
after activation of warning to error conversion.
Create the folder during setup.

Additionally fix a warning in the FAL tests.

Releases: 6.0

Change-Id: I8762a7f2db07edf84294dccb0d9570434040534a
Reviewed-on: http://review.typo3.org/16096
Reviewed-by: Helmut Hummel
Tested-by: Helmut Hummel