While on windows the instantclient sdk also provides the relevant
(import) libs, on linux those libraries are only provided by
instantclient-basiclite package. Therfore setting the Oracle_ROOT env
var to the sdk dir will prevent the libraries to be found on linux.
The FindOracle.cmake module is already adjusted to look for the
libraries in ${Oracle_ROOT}, ${Oracle_ROOT}/lib and
${Oracle_ROOT}/sdk/lib so they should be found correctly even we don't
append 'sdk' for Oracle_ROOT on windows for consistency.
Task-number: QTBUG-128873
Change-Id: Icd211d5b503234de529c339581a4f42f0b5fc726
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
