char/adi: Use min_t(size_t,,) in adi_read() + adi_write()

char/adi: Use min_t(size_t,,) in adi_read() + adi_write()

Replace min() and manual casting of MAX_BUF_SZ with min_t(size_t,,) in
both adi_read() and adi_write().

This matches the initial buffer size calculation:

	ver_buf_sz = min_t(size_t, count, MAX_BUF_SZ);

and makes the code more consistent. No functional changes intended.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Link: https://patch.msgid.link/20250908181354.436680-2-thorsten.blum@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>