Fix Mac builds, for realz.

Change-Id: I63e21b90e5b8a8f016dd04ceca4354793faa5e37
diff --git a/libcutils/fs.c b/libcutils/fs.c
index 8d1da21..286a8eb 100644
--- a/libcutils/fs.c
+++ b/libcutils/fs.c
@@ -148,6 +148,8 @@
     return -1;
 }
 
+#ifndef __APPLE__
+
 int fs_mkdirs(const char* path, mode_t mode) {
     int res = 0;
     int fd = 0;
@@ -231,3 +233,5 @@
     free(buf);
     return res;
 }
+
+#endif