time-utils: fix clang-tidy warning

The code already does size checking to ensure that buffer overruns
are not done, so switch to using operator[] rather than pointer
arithmetic.

```
../redfish-core/include/utils/time_utils.hpp:71:19: error: unsafe pointer arithmetic [-Werror,-Wunsafe-buffer-usage]
        end = fmt.data() + pos;
```

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Iaabe82d7c1621dc27ad10288732609dfd0516d17

1 files changed, 2 insertions, 2 deletions

diff --git a/redfish-core/include/utils/time_utils.hpp b/redfish-core/include/utils/time_utils.hpp
index cb018eff20..e2a6051eec 100644
--- a/redfish-core/include/utils/time_utils.hpp
+++ b/redfish-core/include/utils/time_utils.hpp
@@ -64,11 +64,11 @@ bool fromDurationItem(std::string_view& fmt, const char postfix,
     std::chrono::milliseconds::rep ticks = 0;
     if constexpr (std::is_same_v<FromTime, std::chrono::milliseconds>)
     {
-        end = fmt.data() + std::min<size_t>(pos, 3U);
+        end = &fmt[std::min<size_t>(pos, 3U)];
     }
     else
     {
-        end = fmt.data() + pos;
+        end = &fmt[pos];
     }
 
     auto [ptr, ec] = std::from_chars(fmt.data(), end, ticks);