[gimp] icons: set GEGL_USE_OPENCL=no for symbolic icon inversion

[Øyvind Kolås <ok src gnome org>]

commit dfad0d115edaf9ec7cc23fd255088ac0a345ac3a
Author: Øyvind Kolås <pippin gimp org>
Date:   Tue Sep 20 21:51:27 2016 +0200

    icons: set GEGL_USE_OPENCL=no for symbolic icon inversion
    
    Observed initialization time for OpenCL observed on modern systems has been up
    to 1 second - OpenCL speed ups will not outweigh initialization costs for these
    small icons.

 icons/Symbolic-Inverted/Makefile.am |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/icons/Symbolic-Inverted/Makefile.am b/icons/Symbolic-Inverted/Makefile.am
index 36a20e5..7fc8018 100644
--- a/icons/Symbolic-Inverted/Makefile.am
+++ b/icons/Symbolic-Inverted/Makefile.am
@@ -48,7 +48,7 @@ scalable/%.svg: ../Symbolic/scalable/%.svg $(top_builddir)/tools/invert-svg$(BUI
 # But it doesn't. If someone knows how, feel free to fix it back into
 # a single rule.
 
-MAKE_ICON = mkdir -p `dirname $@`; $(GEGL) $< -o $@ -- gegl:invert-gamma
+MAKE_ICON = mkdir -p `dirname $@`; GEGL_USE_OPENCL=no GEGL_SWAP=ram $(GEGL) $< -o $@ -- gegl:invert-gamma
 
 12/%.png: $(top_srcdir)/icons/Symbolic/12/%.png
        $(MAKE_ICON)