drm: ignore primary argument when using evdi drivers (#25)

* fix: ignore primary if using evdi drivers for displaylink

* style: removed curly braces from evdi if-check

src/backend/drm/DRM.cpp

@@ -622,8 +622,12 @@ bool Aquamarine::CDRMBackend::registerGPU(SP<CSessionDevice> gpu_, SP<CDRMBacken
 
     gpuName = drmName;
 
+    auto drmVerName = drmVer->name ? drmVer->name : "unknown";
+    if (std::string_view(drmVerName) == "evdi")
+        primary = {};
+
     backend->log(AQ_LOG_DEBUG,
-                 std::format("drm: Starting backend for {}, with driver {}{}", drmName ? drmName : "unknown", drmVer->name ? drmVer->name : "unknown",
+                 std::format("drm: Starting backend for {}, with driver {}{}", drmName ? drmName : "unknown", drmVerName,
                              (primary ? std::format(" with primary {}", primary->gpu->path) : "")));
 
     drmFreeVersion(drmVer);