mfd: rtsx: Simplify function return logic

The invoked functions already return zero on success or a negative
errno code so there is no need to open code the logic in the caller.

Signed-off-by: Javier Martinez Canillas <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/rts5209.c

···
 	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, CARD_PWR_CTL, pwr_mask, pwr_on);
 	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, PWR_GATE_CTRL,
 			LDO3318_PWR_MASK, 0x00);
-	err = rtsx_pci_send_cmd(pcr, 100);
-	if (err < 0)
-		return err;
-
-	return 0;
+	return rtsx_pci_send_cmd(pcr, 100);
 }
 
 static int rts5209_card_power_off(struct rtsx_pcr *pcr, int card)

drivers/mfd/rts5227.c

···
 			SD_POWER_MASK, SD_POWER_ON);
 	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, PWR_GATE_CTRL,
 			LDO3318_PWR_MASK, 0x06);
-	err = rtsx_pci_send_cmd(pcr, 100);
-	if (err < 0)
-		return err;
-
-	return 0;
+	return rtsx_pci_send_cmd(pcr, 100);
 }
 
 static int rts5227_card_power_off(struct rtsx_pcr *pcr, int card)

drivers/mfd/rts5229.c

···
 			SD_POWER_MASK, SD_POWER_ON);
 	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, PWR_GATE_CTRL,
 			LDO3318_PWR_MASK, 0x06);
-	err = rtsx_pci_send_cmd(pcr, 100);
-	if (err < 0)
-		return err;
-
-	return 0;
+	return rtsx_pci_send_cmd(pcr, 100);
 }
 
 static int rts5229_card_power_off(struct rtsx_pcr *pcr, int card)

drivers/mfd/rts5249.c

···
 			SD_POWER_MASK, SD_VCC_POWER_ON);
 	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, PWR_GATE_CTRL,
 			LDO3318_PWR_MASK, 0x06);
-	err = rtsx_pci_send_cmd(pcr, 100);
-	if (err < 0)
-		return err;
-
-	return 0;
+	return rtsx_pci_send_cmd(pcr, 100);
 }
 
 static int rtsx_base_card_power_off(struct rtsx_pcr *pcr, int card)

drivers/mfd/rtsx_pcr.c

···
 		tbl++;
 	}
 
-	err = rtsx_pci_send_cmd(pcr, 100);
-	if (err < 0)
-		return err;
-
-	return 0;
+	return rtsx_pci_send_cmd(pcr, 100);
 }
 
 int rtsx_pci_card_pull_ctl_enable(struct rtsx_pcr *pcr, int card)