mtd: spi-nor: cqspi: remove redundant dead code on error return check

Checking for ret < 0 is redundant because a previous check on ret
being non-zero already handles the ret < 0 case. Remove the redundant
code. Found by CoverityScan, CID#1398863, CID#1398864
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Reviewed-by: NRichard Weinberger <richard@nod.at>
Acked-by: NMarek Vasut <marek.vasut@gmail.com>
Signed-off-by: NCyrille Pitchen <cyrille.pitchen@atmel.com>

drivers/mtd/spi-nor/cadence-quadspi.c

@@ -893,7 +893,7 @@ static ssize_t cqspi_write(struct spi_nor *nor, loff_t to,
 	if (ret)
 		return ret;
 
-	return (ret < 0) ? ret : len;
+	return len;
 }
 
 static ssize_t cqspi_read(struct spi_nor *nor, loff_t from,
@@ -913,7 +913,7 @@ static ssize_t cqspi_read(struct spi_nor *nor, loff_t from,
 	if (ret)
 		return ret;
 
-	return (ret < 0) ? ret : len;
+	return len;
 }
 
 static int cqspi_erase(struct spi_nor *nor, loff_t offs)