r600/sfn: Fix default z swizzle for GDS instructions

Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5963>
diff --git a/src/gallium/drivers/r600/sfn/sfn_instruction_gds.cpp b/src/gallium/drivers/r600/sfn/sfn_instruction_gds.cpp
index 002dba6..c84ed64 100644
--- a/src/gallium/drivers/r600/sfn/sfn_instruction_gds.cpp
+++ b/src/gallium/drivers/r600/sfn/sfn_instruction_gds.cpp
@@ -56,7 +56,7 @@
 {
       assert(value);
       m_src_swizzle[1] = value->chan();
-      m_src_swizzle[2] = PIPE_SWIZZLE_MAX;
+      m_src_swizzle[2] = PIPE_SWIZZLE_0;
 }
 
 GDSInstr::GDSInstr(ESDOp op, const GPRVector& dest,