usb: ums: allows using every mmc device with ums.

Before this change ums command only allowed use of mmc 0.
Now this argument can be set.

Changes:
- remove mmc device number checking because it is always positive number
- remove printing "no such device" - it is done by find_mmc_device()

Change-Id: I767e45151ad515c7bef19e6c13087374f5e23c11
Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Cc: Marek Vasut <marex@denx.de>

common/cmd_usb_mass_storage.c

@@ -20,10 +20,11 @@ int do_usb_mass_storage(cmd_tbl_t *cmdtp, int flag,
 	const char *usb_controller = argv[1];
 	const char *mmc_devstring  = argv[2];
 
-	unsigned int dev_num = (unsigned int)(simple_strtoul(mmc_devstring,
-				NULL, 0));
-	if (dev_num)
-		return CMD_RET_USAGE;
+	unsigned int dev_num = simple_strtoul(mmc_devstring, NULL, 0);
+
+	struct ums *ums = ums_init(dev_num);
+	if (!ums)
+		return CMD_RET_FAILURE;
 
 	unsigned int controller_index = (unsigned int)(simple_strtoul(
 					usb_controller,	NULL, 0));
@@ -32,12 +33,6 @@ int do_usb_mass_storage(cmd_tbl_t *cmdtp, int flag,
 		return CMD_RET_FAILURE;
 	}
 
-	struct ums *ums = ums_init(dev_num);
-	if (!ums) {
-		printf("MMC: %u no such device\n", dev_num);
-		return CMD_RET_FAILURE;
-	}
-
 	int rc = fsg_init(ums);
 	if (rc) {
 		error("fsg_init failed");