Bug: WriteCall Fails if CapList.len == 1

[Latrasis]

From @17451k:

Test S() should fail when trying to write to an address below its cap from the kernel-evm1/test/withoutentryproc/syscalls/write.js file is successfully failing with SysCallResponse.WRITEFAILURE, like it is supposed to do, but if we change the write capability from the incorrect (0x8001, 0) to the correct (0x8000, 0) one the test will still fail. It will succeed only if we add some other write capability to the CapArray.

It seems to be that write system calls are failing if there is only one write capability in the CapArray, whether correct or not.