randomconfig fixes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/include/libbb.h b/include/libbb.h
index 6e629d1..97dbe86 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1271,6 +1271,7 @@
  */
 int read_line_input(const char* prompt, char* command, int maxsize, line_input_t *state) FAST_FUNC;
 #else
+#define MAX_HISTORY 0
 int read_line_input(const char* prompt, char* command, int maxsize) FAST_FUNC;
 #define read_line_input(prompt, command, maxsize, state) \
 	read_line_input(prompt, command, maxsize)