mm/mm_heap/mm_sem.c: Fix error that occurs when CONFIG_CPP_HAVE_VARARGS is not defined. In that case, the arguments to the debug macro will all be evaluated even though they are not used any variables that are references must at least be defined.

libs/libc/syslog/lib_syslog.c

@@ -40,6 +40,7 @@
 
 #include <nuttx/config.h>
 
+#include <stdarg.h>
 #include <syslog.h>
 
 #include <nuttx/syslog/syslog.h>
@@ -110,3 +111,4 @@ void syslog(int priority, FAR const IPTR char *fmt, ...)
   vsyslog(priority, fmt, ap);
   va_end(ap);
 }
+