`pcap_lookupdev` may dereference NULL due to incorrect return condition

[MarkLee131]

In function pcap_lookupdev, the return condition is incorrect and can lead to a NULL pointer dereference.

Specifically, the code snippet is:

wine/dlls/wpcap/wpcap.c

Line 476 in 9fa3f75

if (pcap_findalldevs( &devs, errbuf ) == -1 || devs) return NULL;

With the current logic, the function proceeds only when pcap_findalldevs returns success and devs == NULL, and then unconditionally dereferences devs.

Since function pcap_lookupdev is exported (as shownwpcap.spec) and externally callable,

wine/dlls/wpcap/wpcap.spec

Line 47 in 9fa3f75

@ cdecl pcap_lookupdev(ptr)

this results in a reachable crash if pcap_findalldevs returns 0 while leaving devs unset.

The condition likely should be || !devs instead of || devs.