Revert "mptcp: fix possible divide by zero in recvmsg()"

This reverts commit 42ff95b4 which is
commit 0ad529d9 upstream.

It does not build properly due to a previous revert for an Android
kernel abi break.  Bring this one back if it is needed in the future and
the abi is fixed up properly.

Bug: 161946584
Change-Id: Ia735e0ca4ae93bf663fb44fc745d1a232b41b47c
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>