ril: fix a memory leak.

This fixes 'Potential leak of memory pointed to by 'socket'

Bug: None
Test: The warning is gone.
Change-Id: I6afca2b4cf4a027c6fb30f1ad7c74083d70dfdb2
diff --git a/libril/RilSapSocket.cpp b/libril/RilSapSocket.cpp
index 58b4f51..7e4e9c1 100644
--- a/libril/RilSapSocket.cpp
+++ b/libril/RilSapSocket.cpp
@@ -160,6 +160,7 @@
         RilSapSocketList* listItem = (RilSapSocketList*)malloc(sizeof(RilSapSocketList));
         if (!listItem) {
             RLOGE("addSocketToList: OOM");
+            delete socket;
             return;
         }
         listItem->socket = socket;