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

Change-Id: Ia41756e607663d056e7d2fdd7ecbec7e5841a913
diff --git a/logd/LogStatistics.cpp b/logd/LogStatistics.cpp
index 6f3a088..53036e6 100644
--- a/logd/LogStatistics.cpp
+++ b/logd/LogStatistics.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <fcntl.h>
+#include <malloc.h>
 #include <stdarg.h>
 #include <time.h>