IORING_OP_CLOSE fails on fd opened with O_PATH

[Clay Harris <bugs@claycon.org>]

Tested on kernel 5.6.14

$ ./closetest closetest.c

path closetest.c open on fd 3 with O_RDONLY
 ---- io_uring close(3)
 ---- ordinary close(3)
ordinary close(3) failed, errno 9: Bad file descriptor


$ ./closetest closetest.c opath

path closetest.c open on fd 3 with O_PATH
 ---- io_uring close(3)
io_uring close() failed, errno 9: Bad file descriptor
 ---- ordinary close(3)
ordinary close(3) returned 0