Fix typo in xlog.c

"recovery" is not a verb.  Introduced in 68cb5af46c.

src/backend/access/transam/xlog.c

@@ -6101,7 +6101,7 @@ StartupXLOG(void)
 	/*
 	 * Reload shared-memory state for prepared transactions.  This needs to
 	 * happen before renaming the last partial segment of the old timeline as
-	 * it may be possible that we have to recovery some transactions from it.
+	 * it may be possible that we have to recover some transactions from it.
 	 */
 	RecoverPreparedTransactions();