8003690: Example code in JVMTI GetStackTrace documentation is broken

Summary: Fixed to minor errors in example code
Reviewed-by: sspitsyn, dholmes

src/share/vm/prims/jvmti.xml

@@ -2370,11 +2370,11 @@ jint count;
 jvmtiError err;
 
 err = (*jvmti)->GetStackTrace(jvmti, aThread, 0, 5, 
-                               &frames, &count);
+                               frames, &count);
 if (err == JVMTI_ERROR_NONE && count >= 1) {
    char *methodName;
    err = (*jvmti)->GetMethodName(jvmti, frames[0].method, 
-                       &methodName, NULL);
+                       &methodName, NULL, NULL);
    if (err == JVMTI_ERROR_NONE) {
       printf("Executing method: %s", methodName);
    }