7180914: Compilation warning after: 7172967: Eliminate the constMethod's...

7180914: Compilation warning after: 7172967: Eliminate the constMethod's _method backpointer to the methodOop.
Summary: Use read_pointer(J...) to access from 'constMethod' base in name_for_methodOop(), libjvm_db.c.
Reviewed-by: kvn, coleenp

src/os/solaris/dtrace/libjvm_db.c

@@ -516,7 +516,7 @@ name_for_methodOop(jvm_agent_t* J, uint64_t methodOopPtr, char * result, size_t
 
   err = read_pointer(J, methodOopPtr + OFFSET_methodOopDesc_constMethod, &constMethod);
   CHECK_FAIL(err);
-  err = read_pointer(J->P, constMethod + OFFSET_constMethodOopDesc_constants, &constantPool);
+  err = read_pointer(J, constMethod + OFFSET_constMethodOopDesc_constants, &constantPool);
   CHECK_FAIL(err);
 
   /* To get name string */