drm/radeon: Fix integer overflow in radeon_cs_parser_init

The type of size is unsigned, if size is 0x40000000, there will be an
integer overflow, size will be zero after size *= sizeof(uint32_t),
will cause uninitialized memory to be referenced later
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: hackyzh002 <hackyzh002@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon_cs.c

@@ -270,7 +270,8 @@ int radeon_cs_parser_init(struct radeon_cs_parser *p, void *data)
 {
 	struct drm_radeon_cs *cs = data;
 	uint64_t *chunk_array_ptr;
-	unsigned size, i;
+	u64 size;
+	unsigned i;
 	u32 ring = RADEON_CS_RING_GFX;
 	s32 priority = 0;