ASoC: Intel: avs: Use struct_size for struct avs_modcfg_ext size

The struct avs_modcfg_ext structure has a flexible array member for the
pin_fmts array, and the size should be calculated using struct_size to
prevent the potential for overflow with the allocation.

Reviewed-by: Cezary Rojewski <[e-mail]>
Reviewed-by: "Amadeusz Sławiński" <[e-mail]>
Signed-off-by: Jacob Keller <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

sound/soc/intel/avs/path.c

···
 	int ret, i;
 
 	num_pins = tcfg->generic.num_input_pins + tcfg->generic.num_output_pins;
-	cfg_size = sizeof(*cfg) + sizeof(*cfg->pin_fmts) * num_pins;
+	cfg_size = struct_size(cfg, pin_fmts, num_pins);
 
 	cfg = kzalloc(cfg_size, GFP_KERNEL);
 	if (!cfg)