Use std::size_t for array size

Signed-off-by: Martin Stump <martin.stump@mercedes-benz.com>

include/MantleAPI/Common/log_utils.h

@@ -14,6 +14,7 @@
 #include <MantleAPI/Common/i_logger.h>
 
 #include <array>
+#include <cstddef>
 #include <ostream>
 #include <string_view>
 
@@ -23,11 +24,11 @@ namespace mantle_api
 namespace log_utils
 {
 
-static inline constexpr auto kLogLevelNames = std::array<std::string_view, 6>{"Trace", "Debug", "Info", "Warning", "Error", "Critical"};
+static inline constexpr auto kLogLevelNames = std::array<std::string_view, 6U>{"Trace", "Debug", "Info", "Warning", "Error", "Critical"};
 
 [[nodiscard]] constexpr std::string_view ToStringView(LogLevel level) noexcept
 {
-  return (level >= LogLevel::kTrace && level <= LogLevel::kCritical) ? kLogLevelNames.at(static_cast<size_t>(level)) : "Log level out of range";
+  return (level >= LogLevel::kTrace && level <= LogLevel::kCritical) ? kLogLevelNames.at(static_cast<std::size_t>(level)) : "Log level out of range";
 }
 
 }  // namespace log_utils