core: Tear down the sink pipeline even if `NoVideo`
core: Tear down the sink pipeline even if `NoVideo`

This if statement is left-over from aee8f04 (2013-07-02) when we didn't
have seperate source and sink pipelines.  It was introduced to avoid a
hang on teardown due to teardown during a pipeline restart.

Now that there are seperate source and sink pipelines it doesn't make
sense to conditionally teardown the sink pipeline based on whether the
source pipeline is having problems.

LewisHaley/stb-tester,martynjarvis/stb-tester,martynjarvis/stb-tester,stb-tester/stb-tester,LewisHaley/stb-tester,martynjarvis/stb-tester,LewisHaley/stb-tester,martynjarvis/stb-tester,martynjarvis/stb-tester,LewisHaley/stb-tester,stb-tester/stb-tester,LewisHaley/stb-tester,stb-tester/stb-tester,martynjarvis/stb-tester,martynjarvis/stb-tester,LewisHaley/stb-tester,LewisHaley/stb-tester,stb-tester/stb-tester