rocr: Fix missed read lock in ExecutableImpl::FindHostAddress

Change-Id: Ide9b5cc3aa235d3768ebbfd8dc1560bf70fd0743
Signed-off-by: Shane Xiao <shane.xiao@amd.com>
Reviewed-by: Qiang Yu <qiang.yu@amd.com>

runtime/hsa-runtime/loader/executable.cpp

@@ -1088,6 +1088,7 @@ hsa_executable_t AmdHsaCodeLoader::FindExecutable(uint64_t device_address)
 
 uint64_t ExecutableImpl::FindHostAddress(uint64_t device_address)
 {
+  ReaderLockGuard<ReaderWriterLock> reader_lock(rw_lock_);
   for (auto &obj : loaded_code_objects) {
     assert(obj);
     for (auto &seg : obj->LoadedSegments()) {