intel: add INTEL_DEBUG expected value in declaration

Signed-off-by: Marcin Ślusarz <marcin.slusarz@intel.com>
Acked-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6732>

src/intel/dev/gen_debug.c

@@ -39,7 +39,7 @@
 #include "util/debug.h"
 #include "c11/threads.h"
 
-uint64_t INTEL_DEBUG = 0;
+uint64_t intel_debug = 0;
 
 static const struct debug_control debug_control[] = {
    { "tex",         DEBUG_TEXTURE},
@@ -117,7 +117,7 @@ intel_debug_flag_for_shader_stage(gl_shader_stage stage)
 static void
 brw_process_intel_debug_variable_once(void)
 {
-   INTEL_DEBUG = parse_debug_string(getenv("INTEL_DEBUG"), debug_control);
+   intel_debug = parse_debug_string(getenv("INTEL_DEBUG"), debug_control);
 }
 
 void