usb: musb: tusb6010: uninitialized data in tusb_fifo_write_unaligned()

This is writing to the first 1 - 3 bytes of "val" and then writing all
four bytes to musb_writel().  The last byte is always going to be
garbage.  Zero out the last bytes instead.

Fixes: 550a7375 ("USB: Add MUSB and TUSB support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210916135737.GI25094@kiliSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/musb/tusb6010.c

@@ -190,6 +190,7 @@ tusb_fifo_write_unaligned(void __iomem *fifo, const u8 *buf, u16 len)
 	}
 	if (len > 0) {
 		/* Write the rest 1 - 3 bytes to FIFO */
+		val = 0;
 		memcpy(&val, buf, len);
 		musb_writel(fifo, 0, val);
 	}