Expand error message when parser tests found no hook

Expand error message when parser tests found no hook

The existing message is hard to understand and does not mention, that
this is a problem in the parser test itself and not with phpunit.

Before:
1) Warning
The data provider specified for ParserTest_<file>::testParserTest is
invalid.
Problem running hook

After:
1) Warning
The data provider specified for ParserTest_<file>::testParser
Problem running requested parser hook from the test file

Change-Id: I0b4225cc9ab95e8dd048515315c789113dacf39e