test: use snprintf

Author: alandefreitas

src/test_suite/test_suite.hpp

@@ -172,7 +172,7 @@ inline std::string test_output_impl( char const& v )
     else
     {
         char buffer[ 8 ];
-        std::sprintf( buffer, "\\x%02X", static_cast<unsigned char>( v ) );
+        std::snprintf( buffer, 8, "\\x%02X", static_cast<unsigned char>( v ) );
 
         return buffer;
     }