[lldb][nfc] Remove redundant nullptr check

[fdeazeve]

Summary

The make_shared function never returns a nullptr, as such the test for nullptr
is not needed. We also move the empty string check earlier in the if
("oso_object"), as this is cheaper than loading the object file.

[JDevlieghere]

LGTM

lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.cpp

if (pos != m_oso_map.end()) {
                              .getArchName()
                              .str()
                              .c_str());
       comp_unit_info->oso_sp->module_sp = std::make_shared<DebugMapModule>(
           obj_file->GetModule(), GetCompUnitInfoIndex(comp_unit_info), oso_file,
           oso_arch, oso_object ? &oso_object : nullptr, 0,
           oso_object ? comp_unit_info->oso_mod_time : llvm::sys::TimePoint<>());
 
-      if (!comp_unit_info->oso_sp->module_sp || !comp_unit_info->oso_sp->module_sp->GetObjectFile()) {
-        if (oso_object && FileSystem::Instance().Exists(oso_file)) {
-          // If we are loading a .o file from a .a file the "oso_object" will
-          // have a valid value name and if the .a file exists, either the .o
-          // file didn't exist in the .a file or the mod time didn't match.
-          comp_unit_info->oso_load_error.SetErrorStringWithFormat(
-              "\"%s\" object from the \"%s\" archive: "
-              "either the .o file doesn't exist in the archive or the "
-              "modification time (0x%8.8x) of the .o file doesn't match",
-              oso_object.AsCString(), oso_file.GetPath().c_str(),
-              (uint32_t)llvm::sys::toTimeT(comp_unit_info->oso_mod_time));
-        }
-      }
-    }
-  }
+      if (oso_object && !comp_unit_info->oso_sp->module_sp->GetObjectFile() &&
+          FileSystem::Instance().Exists(oso_file)) {
   if (comp_unit_info->oso_sp)
     return comp_unit_info->oso_sp->module_sp.get();
   return nullptr;
 }
 
 bool SymbolFileDWARFDebugMap::GetFileSpecForSO(uint32_t oso_idx,
                                                FileSpec &file_spec) {
   if (oso_idx < m_compile_unit_infos.size()) {