build: Fix build warnings

```
../subprojects/metrics-ipmi-blobs/util.hpp:32:5: error: 'uint64_t' does not name a type
   32 |     uint64_t firmwareTime = 0;
      |     ^~~~~~~~
../subprojects/metrics-ipmi-blobs/util.hpp:18:1: note: 'uint64_t' is defined in header '<cstdint>'; did you forget to '#include <cstdint>'?
   17 | #include <string>
  +++ |+#include <cstdint>
   18 | #include <string_view>
...
../subprojects/nemora-postd/src/serializer.cpp:66:28: error: call of overloaded 'format(const char [15], std::string)' is ambiguous
   66 |     log<level::INFO>(format("NemoraEvent {}", pb.DebugString()).c_str());
```

Change-Id: Id7da1567cdf8cd74d94bd71fa338099b1f0b861e
Signed-off-by: Willy Tu <wltu@google.com>
diff --git a/subprojects/nemora-postd/src/serializer.cpp b/subprojects/nemora-postd/src/serializer.cpp
index 52008b6..69324d9 100644
--- a/subprojects/nemora-postd/src/serializer.cpp
+++ b/subprojects/nemora-postd/src/serializer.cpp
@@ -63,7 +63,8 @@
     pb.set_postcodes_protocol(
         platforms::nemora::proto::EventSeries::NATIVE_32_BIT);
 
-    log<level::INFO>(format("NemoraEvent {}", pb.DebugString()).c_str());
+    log<level::INFO>(
+        format("NemoraEvent {}", pb.DebugString().c_str()).c_str());
     pb.SerializeToString(&result);
     return result;
 }