[SYCL] Fix unused variable errors on post-commit for forward_progress extension (#13793)

The merge of #13389 has caused
post-commit failures due to three unused variable warnings.
This PR fixes that. One of these warnings also revealed a bug in my
original PR.

---------

Co-authored-by: Steffen Larsen <[email protected]>
Co-authored-by: Alexey Sachkov <[email protected]>

Author: 3 people

sycl/source/detail/device_impl.cpp

@@ -860,8 +860,8 @@ bool device_impl::extOneapiCanCompile(
 // coordinationScope
 sycl::ext::oneapi::experimental::forward_progress_guarantee
 device_impl::getHostProgressGuarantee(
-    ext::oneapi::experimental::execution_scope threadScope,
-    ext::oneapi::experimental::execution_scope coordinationScope) {
+    ext::oneapi::experimental::execution_scope,
+    ext::oneapi::experimental::execution_scope) {
   return sycl::ext::oneapi::experimental::forward_progress_guarantee::
       weakly_parallel;
 }
@@ -877,6 +877,7 @@ device_impl::getProgressGuarantee(
       ext::oneapi::experimental::forward_progress_guarantee;
   using execution_scope = ext::oneapi::experimental::execution_scope;
   const int executionScopeSize = 4;
+  (void)coordinationScope;
   int threadScopeNum = static_cast<int>(threadScope);
   // we get the immediate progress guarantee that is provided by each scope
   // between root_group and threadScope and then return the weakest of these.