ath79: fix missing return statement in ar934x_nand

The reset assert and deassert methods currently miss
a return value, leading to a compilation warning.

Return the return-value of reset_control_assert and
reset_control_deassert to fix these warnings.

Suggested-by: Michal Cieslakiewicz <michal.cieslakiewicz@wp.pl>
Signed-off-by: David Bauer <mail@david-bauer.net>

target/linux/ath79/files/drivers/mtd/nand/raw/ar934x_nand.c

@@ -1082,14 +1082,22 @@ static int ar934x_nfc_write_page(struct nand_chip *chip,
 	return err;
 }
 
-static int ar934x_nfc_hw_reset_assert(struct ar934x_nfc *nfc) {
-	reset_control_assert(nfc->rst);
+static int ar934x_nfc_hw_reset_assert(struct ar934x_nfc *nfc)
+{
+	int err;
+
+	err = reset_control_assert(nfc->rst);
 	udelay(250);
+	return err;
 }
 
-static int ar934x_nfc_hw_reset_deassert(struct ar934x_nfc *nfc) {
-	reset_control_deassert(nfc->rst);
+static int ar934x_nfc_hw_reset_deassert(struct ar934x_nfc *nfc)
+{
+	int err;
+
+	err = reset_control_deassert(nfc->rst);
 	udelay(250);
+	return err;
 }
 
 static int ar934x_nfc_hw_init(struct ar934x_nfc *nfc)