mtd: spi: don't return -1 when scan succeed

In spi_flash_scan, 'ret' is initialled to -1, but 'ret' is not always
used to store a return value, in that case, even when the function
succeed, an error (-1) will be returned.
Lets just return 0 if we hit the end of the function.

Signed-off-by: Fabien Parent <fparent@baylibre.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>

drivers/mtd/spi/spi_flash.c

@@ -1000,7 +1000,7 @@ int spi_flash_scan(struct spi_flash *flash)
 {
 	struct spi_slave *spi = flash->spi;
 	const struct spi_flash_info *info = NULL;
-	int ret = -1;
+	int ret;
 
 	info = spi_flash_read_id(flash);
 	if (IS_ERR_OR_NULL(info))
@@ -1166,5 +1166,5 @@ int spi_flash_scan(struct spi_flash *flash)
 	}
 #endif
 
-	return ret;
+	return 0;
 }