build: let 'make clean' remove logs/ again

Before in the recursive automake setting, we had tests/logs/ for
explicitly created test log files. There is a Makefile rule to
remove the logs directory on 'make clean'. The rule broke on moving to
non-recursive make, since now we have logs/, not tests/logs/.

Fix the rule to remove the intended directory.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

Makefile.am

@@ -828,7 +828,7 @@ LA_LOG_COMPILER = $(srcdir)/tests/weston-tests-env
 WESTON_LOG_COMPILER = $(srcdir)/tests/weston-tests-env
 
 clean-local:
-	-rm -rf tests/logs
+	-rm -rf logs
 
 # To remove when automake 1.11 support is dropped
 export abs_builddir