staging: ks7010: change length type to unsigned

Length undergoes type conversion when passed (indirectly) as an
argument for parameter of type 'unsigned int'. If length is negative
this is a bug (the value after conversion is large).

Declare 'length' to be an unsigned type instead of a signed type.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/ks7010/ks7010_sdio.c

@@ -712,7 +712,7 @@ static int ks7010_upload_firmware(struct ks_sdio_card *card)
 	unsigned char *rom_buf;
 	unsigned char rw_data = 0;
 	int ret;
-	int length;
+	unsigned int length;
 	const struct firmware *fw_entry = NULL;
 
 	/* buffer allocate */