mtd: rawnand: stm32_fmc2: Fix fall-through warnings for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix a couple
of warnings by explicitly adding a couple of break statements instead
of letting the code fall through to the next case.

Link: https://github.com/KSPP/linux/issues/115Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210305082953.GA137771@embeddedor

drivers/mtd/nand/raw/stm32_fmc2_nand.c

@@ -531,6 +531,7 @@ static int stm32_fmc2_nfc_ham_correct(struct nand_chip *chip, u8 *dat,
 		switch (b % 4) {
 		case 2:
 			bit_position += shifting;
+			break;
 		case 1:
 			break;
 		default:
@@ -546,6 +547,7 @@ static int stm32_fmc2_nfc_ham_correct(struct nand_chip *chip, u8 *dat,
 		switch (b % 4) {
 		case 2:
 			byte_addr += shifting;
+			break;
 		case 1:
 			break;
 		default: