am 745ddcb2: DO NOT MERGE Only create android_secure mountpoint on the primary external storage volume.

* commit '745ddcb2a6247817dde0790be4c74a81e7b324d4':
  DO NOT MERGE Only create android_secure mountpoint on the primary external storage volume.
diff --git a/DirectVolume.cpp b/DirectVolume.cpp
index 3191cc7..54da964 100644
--- a/DirectVolume.cpp
+++ b/DirectVolume.cpp
@@ -186,6 +186,11 @@
         part_num = 1;
     }
 
+    if (part_num > MAX_PARTITIONS || part_num < 1) {
+        SLOGW("Invalid 'PARTN' value");
+        part_num = 1;
+    }
+
     if (part_num > mDiskNumParts) {
         mDiskNumParts = part_num;
     }