[SYCL][NFC] Update a comment (#6672)

Author: aelovikov-intel

sycl/include/sycl/handler.hpp

@@ -1754,8 +1754,8 @@ class __SYCL_EXPORT handler {
   }
 
   // This version of parallel_for may handle one or more reductions packed in
-  // \p Rest argument. Note thought that the last element in \p Rest pack is
-  // the kernel function.
+  // \p Rest argument. The last element in \p Rest pack is the kernel function,
+  // everything else is reduction(s).
   // TODO: this variant is currently enabled for 2+ reductions only as the
   // versions handling 1 reduction variable are more efficient right now.
   //