flash/nor/sh_qspi: Fix dead assignment

Change-Id: I6a99076fea30062535e615244895698e51107441
Signed-off-by: Marc Schink <dev@zapb.de>
Reviewed-on: http://openocd.zylin.com/5645
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

src/flash/nor/sh_qspi.c

@@ -654,7 +654,7 @@ static int sh_qspi_read(struct flash_bank *bank, uint8_t *buffer,
 	destroy_reg_param(&reg_params[2]);
 	destroy_reg_param(&reg_params[3]);
 
-	return ERROR_OK;
+	return ret;
 }
 
 /* Return ID of flash device */