Define YY_NO_INPUT in flex scanner to avoid warning

Signed-off-by: Andi Kleen <ak@linux.intel.com>

mce.lex

diff --git a/mce.lex b/mce.lex
index ca5b27c..cc324b2 100644
--- a/mce.lex
+++ b/mce.lex
@@ -33,6 +33,8 @@
 int yylineno;
 
 static int lookup_symbol(const char *);
+
+#define YY_NO_INPUT 1
 %}
 
 %option nounput