docs: fix typo in testing.rst
Coverage section refers to "check-lcoc" target, should be
"check-lcov".
Acked-by: Flavio Leitner
@@ -99,7 +99,7 @@ Coverage
If the build was configured with ``--enable-coverage`` and the ``lcov`` utility
is installed, you can run the testsuite and generate a code coverage report by
-using the ``check-lcoc`` target::
+using the ``check-lcov`` target::
$ make check-lcov
