Add missing <malloc.h> and <string.h> includes.

Change-Id: Ia41756e607663d056e7d2fdd7ecbec7e5841a913
diff --git a/adf/libadfhwc/adfhwc.cpp b/adf/libadfhwc/adfhwc.cpp
index 57e09eb..21f245e 100644
--- a/adf/libadfhwc/adfhwc.cpp
+++ b/adf/libadfhwc/adfhwc.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <fcntl.h>
+#include <malloc.h>
 #include <poll.h>
 #include <pthread.h>
 #include <sys/resource.h>