interconnect: qcom: Simplify the vcd compare function

Let's simplify the cmp_vcd() function and replace the conditionals
with just a single statement, which also improves readability.
Reviewed-by: NMike Tipton <mdtipton@codeaurora.org>
Link: https://lore.kernel.org/r/20201013171923.7351-1-georgi.djakov@linaro.orgSigned-off-by: NGeorgi Djakov <georgi.djakov@linaro.org>

drivers/interconnect/qcom/bcm-voter.c

@@ -41,17 +41,10 @@ struct bcm_voter {
 
 static int cmp_vcd(void *priv, struct list_head *a, struct list_head *b)
 {
-	const struct qcom_icc_bcm *bcm_a =
-			list_entry(a, struct qcom_icc_bcm, list);
-	const struct qcom_icc_bcm *bcm_b =
-			list_entry(b, struct qcom_icc_bcm, list);
-
-	if (bcm_a->aux_data.vcd < bcm_b->aux_data.vcd)
-		return -1;
-	else if (bcm_a->aux_data.vcd == bcm_b->aux_data.vcd)
-		return 0;
-	else
-		return 1;
+	const struct qcom_icc_bcm *bcm_a = list_entry(a, struct qcom_icc_bcm, list);
+	const struct qcom_icc_bcm *bcm_b = list_entry(b, struct qcom_icc_bcm, list);
+
+	return bcm_a->aux_data.vcd - bcm_b->aux_data.vcd;
 }
 
 static u64 bcm_div(u64 num, u32 base)