[libomptarget] [amdgpu] Fix copy-paste error setting NumThreads for a corner case.

[dhruvachak]

Summary

Fix the case where NumTeams was set incorrectly instead of NumThreads

[JonChesterfield]

Could change these to std::min, or add a one line clamp function to avoid repeating either variable

openmp/libomptarget/plugins/amdgpu/src/rtl.cpp

int32_t __tgt_rtl_init_device(int device_id) {
   }
 
   // Set default number of threads
   DeviceInfo.NumThreads[device_id] = RTLDeviceInfoTy::Default_WG_Size;
   DP("Default number of threads set according to library's default %d\n",
      RTLDeviceInfoTy::Default_WG_Size);
   if (DeviceInfo.NumThreads[device_id] >
       DeviceInfo.ThreadsPerGroup[device_id]) {
-    DeviceInfo.NumTeams[device_id] = DeviceInfo.ThreadsPerGroup[device_id];
+    DeviceInfo.NumThreads[device_id] = DeviceInfo.ThreadsPerGroup[device_id];
     DP("Default number of threads exceeds device limit, capping at %d\n",
        DeviceInfo.ThreadsPerGroup[device_id]);
   }
 
   DP("Device %d: default limit for groupsPerDevice %d & threadsPerGroup %d\n",
      device_id, DeviceInfo.GroupsPerDevice[device_id],
      DeviceInfo.ThreadsPerGroup[device_id]);