hwc: store gscaler configuration in correct slot

gsc_map is indexed by window #, not by layer #

Change-Id: I6f89e9b0de3787e0ab2aeb490bb6eb3c86bdcf8a
Signed-off-by: Greg Hackmann <ghackmann@google.com>
diff --git a/libhwc/hwc.cpp b/libhwc/hwc.cpp
index c2cb284..271542d 100644
--- a/libhwc/hwc.cpp
+++ b/libhwc/hwc.cpp
@@ -927,9 +927,9 @@
                         private_handle_t::dynamicCast(layer.handle);
                 if (exynos5_format_requires_gscaler(handle->format)) {
                     ALOGV("\tusing gscaler %u", AVAILABLE_GSC_UNITS[nextGsc]);
-                    pdev->bufs.gsc_map[i].mode =
+                    pdev->bufs.gsc_map[nextWindow].mode =
                             exynos5_gsc_map_t::GSC_M2M;
-                    pdev->bufs.gsc_map[i].idx = nextGsc++;
+                    pdev->bufs.gsc_map[nextWindow].idx = nextGsc++;
                 }
             }
             nextWindow++;