Remove use of deprecated `array.fromstring` method (GH-17332)

(cherry picked from commit 386d00cc341b549800776b906bfc6b20ea40c7db)

Co-authored-by: David Coles <coles.david@gmail.com>
diff --git a/Doc/library/socket.rst b/Doc/library/socket.rst
index 12b9091..ae82e43 100644
--- a/Doc/library/socket.rst
+++ b/Doc/library/socket.rst
@@ -1394,9 +1394,9 @@
           fds = array.array("i")   # Array of ints
           msg, ancdata, flags, addr = sock.recvmsg(msglen, socket.CMSG_LEN(maxfds * fds.itemsize))
           for cmsg_level, cmsg_type, cmsg_data in ancdata:
-              if (cmsg_level == socket.SOL_SOCKET and cmsg_type == socket.SCM_RIGHTS):
+              if cmsg_level == socket.SOL_SOCKET and cmsg_type == socket.SCM_RIGHTS:
                   # Append data, ignoring any truncated integers at the end.
-                  fds.fromstring(cmsg_data[:len(cmsg_data) - (len(cmsg_data) % fds.itemsize)])
+                  fds.frombytes(cmsg_data[:len(cmsg_data) - (len(cmsg_data) % fds.itemsize)])
           return msg, list(fds)
 
    .. availability:: most Unix platforms, possibly others.