iw: fix endless loop inside handle_mgmt_dump
iw: fix endless loop inside handle_mgmt_dump

passing -1 will break the while loop further down in the code.

Signed-off-by: John Crispin <a51dda7c7ff50b61eaea0444371f4a6a9301e501@phrozen.org>
Signed-off-by: Johannes Berg <bff32994ff0f8d048f262a8388145a71b6071bfe@intel.com>

greearb/iw-ct,greearb/iw-ct