[SYCL] Eliminate use of dereference of past-the-end iterator in unit tests (#4070)

Signed-off-by: Kanaev <[email protected]>

Author: sergei

sycl/unittests/helpers/PiImage.hpp

@@ -128,7 +128,7 @@ template <typename T> class PiArray {
   }
 
   typename T::NativeType *begin() { return &*MEntries.begin(); }
-  typename T::NativeType *end() { return &*MEntries.end(); }
+  typename T::NativeType *end() { return begin() + MEntries.size(); }
 
 private:
   std::vector<T> MMockEntries;
@@ -200,7 +200,7 @@ class PiImage {
         ManifestStart,
         ManifestEnd,
         &*MBinary.begin(),
-        &*MBinary.end(),
+        (&*MBinary.begin()) + MBinary.size(),
         MOffloadEntries.begin(),
         MOffloadEntries.end(),
         MPropertySet.begin(),