flash: Fix CFI buffer size bug

Fix bug introduced by 9c048b523413ae5f3ff34e00cf57569c3368ab51.

The cfi_flash.c driver cast the flash buffer size to a uchar in
flash_write_cfibuffer(). On some flash parts, (tested on Numonyx
part PC32F512M29EWH), the buffer size is 1KB. Remove the cast to
uchar to enable buffer sizes to be larger.

Signed-off-by: John Schmoller <jschmoller@xes-inc.com>
Signed-off-by: Stefan Roese <sr@denx.de>

drivers/mtd/cfi_flash.c

@@ -1001,7 +1001,7 @@ static int flash_write_cfibuffer (flash_info_t * info, ulong dest, uchar * cp,
 #endif
 		flash_write_cmd(info, sector, offset, AMD_CMD_WRITE_TO_BUFFER);
 		cnt = len >> shift;
-		flash_write_cmd(info, sector, offset, (uchar)cnt - 1);
+		flash_write_cmd(info, sector, offset, cnt - 1);
 
 		switch (info->portwidth) {
 		case FLASH_CFI_8BIT: