Don't define the input() function ifdef YY_NO_INPUT.

This was previously done for the input() function.

Submitted by:	Norberto Lopes <nblopes.ml at gmail.com>

usr.bin/lex/flex.skl

@@ -979,6 +979,7 @@ void yyFlexLexer::yyunput( int c, char* yy_bp )
 
 
 %-
+#ifndef YY_NO_INPUT
 #ifdef __cplusplus
 static int yyinput()
 #else
@@ -1054,6 +1055,7 @@ int yyFlexLexer::yyinput()
 
 	return c;
 	}
+#endif /* ifndef YY_NO_INPUT */
 
 
 %-