Handle NULL result of strdup.

The check is needed to satisfy @NonNull annotation in Java API.

BUG=26758882

Change-Id: Ie2a45a05593f2a48e23f3ca90302b78ca78a980e
diff --git a/media/mtp/MtpObjectInfo.cpp b/media/mtp/MtpObjectInfo.cpp
index 0573104..43b745f 100644
--- a/media/mtp/MtpObjectInfo.cpp
+++ b/media/mtp/MtpObjectInfo.cpp
@@ -77,6 +77,7 @@
 
     if (!packet.getString(string)) return false;
     mName = strdup((const char *)string);
+    if (!mName) return false;
 
     if (!packet.getString(string)) return false;
     if (parseDateTime((const char*)string, time))
@@ -88,6 +89,7 @@
 
     if (!packet.getString(string)) return false;
     mKeywords = strdup((const char *)string);
+    if (!mKeywords) return false;
 
     return true;
 }