Merge branch 'rxrpc-miscellaneous-fixes'

David Howells says:

====================
rxrpc: Miscellaneous fixes

Here are some miscellaneous fixes for rxrpc:

 (1) Fix assertion failure due to preallocation collision.

 (2) Fix oops due to prealloc backlog struct not yet having been allocated
     if no service calls have yet been preallocated.
====================

Link: https://patch.msgid.link/20250708211506.2699012-1-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>