bound control name and value copies in tb_parse_amixer

[jmestwa-coder]

tb_parse_amixer copies the parsed control name and value into fixed 128-byte stack buffers with no length check on the data read from the control script:

• control_name: len comes from the cset name="..." quote delimiters, never capped to TB_MAX_CTL_NAME_CHARS
• control_params: same unchecked copy for the value after the closing quote
• a name longer than the buffer overflows the stack; the sibling tb_parse_sofctl avoids this by using strndup
  Reject over-length fields before each memcpy.

[sofci]

Can one of the admins verify this patch?

reply test this please to run this test once

[Copilot]

Pull request overview

This PR hardens tb_parse_amixer() in the SOF testbench by rejecting over-length control names and values parsed from control scripts, preventing stack buffer overflows when copying into fixed-size buffers.

Changes:

• Add bounds checks for the parsed control name length before copying into control_name.
• Add bounds checks for the parsed control value length before copying into control_params.