squashfs_utils: fix build on Mac

Mac's libc doesn't define TEMP_FAILURE_RETRY. Include a definition
from libcutils.

Change-Id: I72c67d17614f79964fd684fd728242bee3e0599c
diff --git a/squashfs_utils/squashfs_utils.c b/squashfs_utils/squashfs_utils.c
index 1d619ce..1db424b 100644
--- a/squashfs_utils/squashfs_utils.c
+++ b/squashfs_utils/squashfs_utils.c
@@ -16,6 +16,7 @@
 
 #include "squashfs_utils.h"
 
+#include <cutils/fs.h>
 #include <cutils/klog.h>
 #include <errno.h>
 #include <fcntl.h>