EXT4: Fix number base handling of "ext4write" command

Unlike other commands (for example, "fatwrite"), ext4write would
interpret the "sizebytes" as decimal number.  This is not only
inconsistend and unexpected to most users, it also breaks usage
like this:

	tftp ${addr} ${name}
	ext4write mmc 0:2 ${addr} ${filename} ${filesize}

Change this to use the standard notation of base 16 input format.
See also commit b770e88a

WARNING: this is a change to the user interface!!
Signed-off-by: NWolfgang Denk <wd@denx.de>
Cc: Uma Shankar <uma.shankar@samsung.com>
Cc: Stephen Warren <swarren@nvidia.com>

common/cmd_ext4.c

@@ -79,8 +79,8 @@ int do_ext4_write(cmd_tbl_t *cmdtp, int flag, int argc,
 	/* get the address in hexadecimal format (string to int) */
 	ram_address = simple_strtoul(argv[3], NULL, 16);
 
-	/* get the filesize in base 10 format */
-	file_size = simple_strtoul(argv[5], NULL, 10);
+	/* get the filesize in hexadecimal format */
+	file_size = simple_strtoul(argv[5], NULL, 16);
 
 	/* set the device as block device */
 	ext4fs_set_blk_dev(dev_desc, &info);