fix: remove redundant len() call on buffer size

[RGB-loop]

Problem

The u.buffer() method returns a list[str] (list of blob IDs). The code incorrectly calls len() twice:

• First len(u.buffer(...)) makes left an integer
• Then len(left) tries to call len() on an integer, causing TypeError

Solution

Remove the redundant len() call, keeping left as the count directly. Use left in the condition and print statement.

Testing

• Verified the buffer API returns list[str]
• Code now properly checks and displays the remaining buffer count