[libomptarget] Fix libomptarget.rtl.amdgpu.so installation

If AMD GPUs don't exist when building libomptarget, the early return causes skipping the plugin installation.

GitOrigin-RevId: 0fa04b6e2cd2169a8e3d22ae879394dbf07c0466
diff --git a/libomptarget/plugins-nextgen/amdgpu/CMakeLists.txt b/libomptarget/plugins-nextgen/amdgpu/CMakeLists.txt
index 9e0ea08..8fbfe4d 100644
--- a/libomptarget/plugins-nextgen/amdgpu/CMakeLists.txt
+++ b/libomptarget/plugins-nextgen/amdgpu/CMakeLists.txt
@@ -109,7 +109,6 @@
 else()
   libomptarget_say("Not generating AMDGPU tests, no supported devices detected."
                    " Use 'LIBOMPTARGET_FORCE_AMDGPU_TESTS' to override.")
-  return()
 endif()
 
 # Install plugin under the lib destination folder.