[gegl] tests: clean up test outputs for distcheck

[Daniel Sabo <daniels src gnome org>]

commit c7691209bbbd26d479e47b0c8f0dc259bbd67351
Author: Daniel Sabo <DanielSabo gmail com>
Date:   Sat Oct 5 22:16:54 2013 -0700

    tests: clean up test outputs for distcheck

 tests/simple/Makefile.am |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/tests/simple/Makefile.am b/tests/simple/Makefile.am
index e50ff67..de888ea 100644
--- a/tests/simple/Makefile.am
+++ b/tests/simple/Makefile.am
@@ -43,3 +43,6 @@ AM_CFLAGS = $(DEP_CFLAGS) $(BABL_CFLAGS)
 # Common libs
 LIBS = $(top_builddir)/gegl/libgegl-$(GEGL_API_VERSION).la     \
        $(DEP_LIBS) $(BABL_LIBS)
+
+clean-local:
+       rm -f test-exp-combine.hdr test-exp-combine-diff.png