net-test: fix nduseropt parsing when multiple are present Tested: manually on UML (on kernels both with and without PIO nduseropt fix) Signed-off-by: Maciej Żenczykowski <[email protected]> Bug: 363210101 Change-Id: Ia75574fad074914e60b227bc3ec788137175999e Merged-In: Iafc98babfc451125e8de7700a773d36b15a67b29 (cherry picked from commit 79cb2927bbe0449d690b501df233149d576840bb)