Add missing includes.

Change-Id: I91730363386dae6ecb2193ec8f50ba9f8fc0ad60
diff --git a/modules/vibrator/vibrator.c b/modules/vibrator/vibrator.c
index ce4c03c..6b3ce57 100644
--- a/modules/vibrator/vibrator.c
+++ b/modules/vibrator/vibrator.c
@@ -19,6 +19,7 @@
 
 #include <cutils/log.h>
 
+#include <malloc.h>
 #include <stdio.h>
 #include <unistd.h>
 #include <fcntl.h>