fix(hid): Store client instance per-device instead of per-class (#262)

* fix(hid): Store client instance per-device instead of per-class

* Address review feedback on per-instance HID client copy

Three issues fixed, discovered during maintainer review:

1. Memory leak in standalone activation error path (entry.c):
   _ux_host_class_hid_client_activate_wait() set hid_client to NULL
   without freeing the per-instance copy allocated in client_search.
   The HID_ENUM_ERROR handler destroys the hid struct without freeing
   hid_client, so the copy was leaked on every standalone activation
   failure. Fixed by freeing hid_client before clearing it.

2. Variable declared inside if-block (client_search.c):
   hid_client_instance was declared inside the if (status == UX_SUCCESS)
   block, which is a C99 feature. USBX targets C89/C90 embedded
   toolchains. Moved to the top of the function with other locals.

3. Trailing whitespace throughout both changed files:
   The PR introduced trailing spaces on most comment-block lines.
   Reverted all affected lines to their original whitespace.

Co-authored-by: Copilot <[email protected]>

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Co-authored-by: Frédéric Desbiens <[email protected]>
Co-authored-by: Copilot <[email protected]>

0 files changed, 0 insertions, 0 deletions