[SYCL] Try to load next plugins if plugin fails (#3641)

Do not stop loading next plugins if the current one fails to initialize.

Author: vladimirlaz

sycl/source/detail/platform_impl.cpp

@@ -100,11 +100,11 @@ vector_class<platform> platform_impl::get_platforms() {
   for (unsigned int i = 0; i < Plugins.size(); i++) {
 
     pi_uint32 NumPlatforms = 0;
-    // Just return zero platforms if plugin fails to initialize.
+    // Move to the next plugin if the plugin fails to initialize.
     // This way platforms from other plugins get a chance to be discovered.
     if (Plugins[i].call_nocheck<PiApiKind::piPlatformsGet>(
             0, nullptr, &NumPlatforms) != PI_SUCCESS)
-      return Platforms;
+      continue;
 
     if (NumPlatforms) {
       vector_class<RT::PiPlatform> PiPlatforms(NumPlatforms);