r600/sfn: Initialize GPRValue member m_pin_to_channel.

Fix defects reported by Coverity Scan.

Uninitialized scalar field (UNINIT_CTOR)
uninit_member: Non-static class member m_pin_to_channel is not
initialized in this constructor nor in any functions that it calls.

Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Gert Wollny <gert.wollny@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6830>
diff --git a/src/gallium/drivers/r600/sfn/sfn_value_gpr.cpp b/src/gallium/drivers/r600/sfn/sfn_value_gpr.cpp
index dba5c04..f4dcb68 100644
--- a/src/gallium/drivers/r600/sfn/sfn_value_gpr.cpp
+++ b/src/gallium/drivers/r600/sfn/sfn_value_gpr.cpp
@@ -38,7 +38,8 @@
    Value(Value::gpr, chan),
    m_sel(sel),
    m_base_offset(base_offset),
-   m_input(false)
+   m_input(false),
+   m_pin_to_channel(false)
 {
 }
 
@@ -46,7 +47,8 @@
    Value(Value::gpr, chan),
    m_sel(sel),
    m_base_offset(0),
-   m_input(false)
+   m_input(false),
+   m_pin_to_channel(false)
 {
 }