toolchain-scripts.bbclass: fix bitbake-setup compatibility

Pass the BITBAKEDIR parameter to oe-init-build-env when called from the
environment-setup script. This fixes compatibility with bitbake-setup,
which places bitbake in a different directory structure than the
standard poky repository layout where bitbake is located alongside
oe-init-build-env.

The issue was discovered when running the oe-selftest test
DevtoolIdeSdkTests.test_devtool_ide_sdk_shared_sysroots, which failed
because the environment-setup script was not able to find bitbake.

File ".../openembedded-core/meta/lib/oeqa/selftest/cases/devtool.py",
  line 2955, in test_devtool_ide_sdk_shared_sysroots
  self.assertExists(cmake_native)
  ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^
File ".../openembedded-core/meta/lib/oeqa/selftest/case.py", line 251,
  in assertExists
  raise self.failureException(msg)
AssertionError: 'Error: The bitbake directory (/tmp/devtoolqah9ndff2x/bitbake)
  does not exist!  Please ensure a copy of bitbake exists at this location or
  specify an alternative path on the command line\n
  .../build-st/tmp/sysroots/x86_64/usr/bin/cmake' does not exist

(From OE-Core rev: f31903ca484bad68708ec510e25ea33234f5c0ce)

Signed-off-by: Adrian Freihofer <adrian.freihofer@siemens.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

0 files changed, 0 insertions, 0 deletions