fixed clang warning about uninitialized values

include/spdlog/details/os.h

@@ -238,13 +238,17 @@ inline size_t filesize(FILE *f)
     int fd = fileno(f);
     // 64 bits(but not in osx or cygwin, where fstat64 is deprecated)
 #if !defined(__FreeBSD__) && !defined(__APPLE__) && (defined(__x86_64__) || defined(__ppc64__)) && !defined(__CYGWIN__)
-    struct stat64 st;
+    struct stat64 st
+    {
+    };
     if (fstat64(fd, &st) == 0)
     {
         return static_cast<size_t>(st.st_size);
     }
 #else // unix 32 bits or cygwin
-    struct stat st;
+    struct stat st
+    {
+    };
     if (fstat(fd, &st) == 0)
     {
         return static_cast<size_t>(st.st_size);

include/spdlog/details/registry.h

@@ -249,7 +249,7 @@ private:
     size_t _async_q_size = 0;
     async_overflow_policy _overflow_policy = async_overflow_policy::block_retry;
     std::function<void()> _worker_warmup_cb;
-    std::chrono::milliseconds _flush_interval_ms;
+    std::chrono::milliseconds _flush_interval_ms{std::chrono::milliseconds::zero()};
     std::function<void()> _worker_teardown_cb;
 };