epee: add do while(0) around brace statement in a macro

Allows use in more complex expressions

contrib/epee/include/misc_log_ex.h

@@ -169,7 +169,7 @@ namespace debug
 
 
 #define ASSERT_MES_AND_THROW(message) {LOG_ERROR(message); std::stringstream ss; ss << message; throw std::runtime_error(ss.str());}
-#define CHECK_AND_ASSERT_THROW_MES(expr, message) {if(!(expr)) ASSERT_MES_AND_THROW(message);}
+#define CHECK_AND_ASSERT_THROW_MES(expr, message) do {if(!(expr)) ASSERT_MES_AND_THROW(message);} while(0)
 
 
 #ifndef CHECK_AND_ASSERT