ibcore: Fix use-after-free access in ucma_close()

The error in ucma_create_id() left ctx in the list of contexts belong
to ucma file descriptor. The attempt to close this file descriptor causes
to use-after-free accesses while iterating over such list.

Linux commit:
ed65a4dc22083e73bac599ded6a262318cad7baf

PR: 264650
MFC after: 1 week
Sponsored by: NVIDIA Networking