[llvm] [Offload] Fix assumptions on symbols after #124846 (PR #126238)

[Shilei Tian via llvm-commits]

shiltian wrote:

It is a little bit weird to have a PR got merged w/o review. You can potentially put an `[NFC]` in the title and shoot it to the branch directly w/o a PR. :-)

https://github.com/llvm/llvm-project/pull/126238