Flush buffer after newline in putc, fputc, and puts (but not fputs)

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3607 42af7a65-404d-4744-a932-0658087f49c3

lib/stdio/lib_libvsprintf.c

@@ -1136,6 +1136,8 @@ int lib_vsprintf(FAR struct lib_outstream_s *obj, const char *src, va_list ap)
 #ifdef CONFIG_STDIO_LINEBUFFER
            if (*src == '\n')
              {
+               /* Should return an error on a failure to flush */
+
                (void)obj->flush(obj);
              }
 #endif