The corresponding tapset/syscalls.stp has: probe syscall.epoll_create = kernel.function("sys_epoll_create1").call !, kernel.function("sys_epoll_create").call ?
The reason why it is done this way in syscalls.stp is that in the kernel sys_epoll_create is just a wrapper around sys_epoll_create1. This way we ignore the sys_epoll_create call, and only catch the sys_epoll_create1 call on kernels with sys_epoll_create1. Unfortunately, as bug #11424 notes, '!' (optional and sufficient) doesn't work for kprobe.function probes. So, the above logic will be difficult to duplicate in tapset/nd_syscalls.stp.
Now that bug #11424 and bug #14378 are fixed, this bug can be addressed. Fixed in commit 3b9ac30.