ASoC: wm_hubs: Use explicit casts for converting to signed

Should be no behaviour change.

Signed-off-by: Mark Brown <[e-mail]>

sound/soc/codecs/wm_hubs.c

···
 			hubs->dcs_codes_l, hubs->dcs_codes_r);
 
 		/* HPOUT1R */
-		offset = reg_r;
+		offset = (s8)reg_r;
 		offset += hubs->dcs_codes_r;
 		dcs_cfg = (u8)offset << WM8993_DCS_DAC_WR_VAL_1_SHIFT;
 
 		/* HPOUT1L */
-		offset = reg_l;
+		offset = (s8)reg_l;
 		offset += hubs->dcs_codes_l;
 		dcs_cfg |= (u8)offset;