Ensure DebugInfoSourceCacheRoot.getValue() is only read when already set

Author: olpaw

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/image/NativeImageDebugInfoProvider.java

@@ -244,7 +244,7 @@ private static ResolvedJavaType getOriginal(ResolvedJavaType javaType) {
         return null;
     }
 
-    private static final Path cachePath = SubstrateOptions.getDebugInfoSourceCacheRoot();
+    private final Path cachePath = SubstrateOptions.getDebugInfoSourceCacheRoot();
 
     private abstract class NativeImageDebugFileInfo implements DebugFileInfo {
         private Path fullFilePath;