Add missing includes.

Change-Id: I06ea08400efa511e627be37a4fd70fbdfadea2e6
diff --git a/fuse_sdcard_provider.c b/fuse_sdcard_provider.c
index 19fb52d..ca8c914 100644
--- a/fuse_sdcard_provider.c
+++ b/fuse_sdcard_provider.c
@@ -16,6 +16,7 @@
 
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 #include <errno.h>
 #include <pthread.h>
 #include <sys/mount.h>