Fix some static analysis "problems"

Bug:375532

src/MQTTPersistenceDefault.c

@@ -662,7 +662,8 @@ int keysUnix(char *dirname, char ***keys, int *nkeys)
 		goto exit;
 	}
 
-	if (nfkeys != 0 )
+	if (nfkeys != 0)
+	{
 		fkeys = (char **)malloc(nfkeys * sizeof(char *));
 
 		/* copy the keys */
@@ -691,6 +692,7 @@ int keysUnix(char *dirname, char ***keys, int *nkeys)
 			rc = MQTTCLIENT_PERSISTENCE_ERROR;
 			goto exit;
 		}
+	}
 
 	*nkeys = nfkeys;
 	*keys = fkeys;

src/Socket.c

@@ -616,6 +616,9 @@ int Socket_new(char* addr, int port, int* sock)
 			res = res->ai_next;
 		}
 
+		if (result == NULL)
+			rc = -1;
+		else
 #if defined(AF_INET6)
 		if (result->ai_family == AF_INET6)
 		{