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

Change-Id: Ia41756e607663d056e7d2fdd7ecbec7e5841a913
diff --git a/toolbox/lsof.c b/toolbox/lsof.c
index bee981d..982f5aa 100644
--- a/toolbox/lsof.c
+++ b/toolbox/lsof.c
@@ -35,6 +35,7 @@
 #include <libgen.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 
 #include <pwd.h>