UCT/CUDA_IPC: cuIpcGetMemHandle pass confused addr in cuda_ipc_md.c

[ACEMaravilla]

Describe the bug

in ucx/src/uct/cuda/cuda_ipc/cuda_ipc_md.c line: 240
when get mem IPC handle：
cuIpcGetMemHandle(&key->ph.handle.legacy, (CUdeviceptr)addr));

the second param should not ’addr‘, but ‘key->d_bptr’,
because key->d_bptr is mean allocated device memory base ptr

in document says

dptr
- Base pointer to previously allocated device memory

'addr' however may represent to baseaddr+offset ,
then cuIpcGetMemHandle return is undefined，may result to cumemcpy bug

BTW，I have a test to validate what would return when addr is base + offset

allocation base=0x7e3e4de00000 size=1048576
offset address=0x7e3e4de80000 offset=524288
cuMemGetAddressRange(offset address): base=0x7e3e4de00000 size=1048576
cuIpcGetMemHandle(base): CUDA_SUCCESS (0), no error
cuIpcGetMemHandle(base + offset): CUDA_SUCCESS (0), no error
both calls succeeded; opaque handles are identical

which mean pass base address or base + offset both will return same base handle

SO at the semantic level here should pass key->d_bptr，though now pass 'addr' may not lead to mismatch