IMPALA-7073: skip TestScannerReservation on non-miniclusters
IMPALA-7073: skip TestScannerReservation on non-miniclusters

The test is (sort of) tuned for miniclusters and is very targeted
to testing a specific code path, rather than general functional
correctness, so we don't really need coverage on all filesystems.

Change-Id: I7952f780cff80c08a6cbef898bf7b95c9bba5f6a
Reviewed-on: http://gerrit.cloudera.org:8080/10533
Reviewed-by: Thomas Marshall <19143d3de8b13ab65aabdc921d14db5a16735b95@cmu.edu>
Tested-by: Impala Public Jenkins <039b6b20426ff68ebe492b3021890d8c8fd010c9@cloudera.com>

cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala