pkgdata.py: avoid target-sdk-dummy-provides to mess things up

Sometimes we meet the following failure for the test_lookup_recipe
test case.

  AssertionError: 'zlib\nbusybox is in the RPROVIDES of target-sdk-provid[32 chars]ummy' != 'zlib\nbusybox'
    zlib
  + busybox- busybox is in the RPROVIDES of target-sdk-provides-dummy:
  - target-sdk-provides-dummy

This is because target-sdk-provides-dummy rprovides busybox.

So clean things up to avoid failure.

(From OE-Core rev: 7b5a069d4f11e36a1c407c4212aba5aafaf4ee7f)

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oeqa/selftest/cases/pkgdata.py

@@ -13,6 +13,7 @@ class OePkgdataUtilTests(OESelftestTestCase):
         super(OePkgdataUtilTests, cls).setUpClass()
         # Ensure we have the right data in pkgdata
         cls.logger.info('Running bitbake to generate pkgdata')
+        bitbake('target-sdk-provides-dummy -c clean')
         bitbake('busybox zlib m4')
 
     @OETestID(1203)