UCX and enable mca dso do not mix

[hppritcha]

Thank you for taking the time to submit an issue!

Background information

What version of Open MPI are you using? (e.g., v3.0.5, v4.0.2, git branch name and hash, etc.)

main and v5.0.x

RHEL8
x86_64
connectx5

ucx-rdmacm-1.12.0-1.55103.x86_64
ucx-cma-1.12.0-1.55103.x86_64
ucx-xpmem-1.12.0-1.55103.x86_64
ucx-1.12.0-1.55103.x86_64
ucx-ib-1.12.0-1.55103.x86_64
ucx-devel-1.12.0-1.55103.x86_64
ucx-knem-1.12.0-1.55103.x86_64

to reproduce:

./configure --with-ucx --enable-mca-dso --prefix=favoritepath
make install

the resulting ompi_info will segfault with a traceback like:

[er-head:1511505:0:1511505] Caught signal 11 (Segmentation fault: address not mapped to object at address 0x7fffeded5298)
==== backtrace (tid:1511505) ====
 0 0x0000000000012c20 .annobin_sigaction.c()  sigaction.c:0
 1 0x0000000000043529 var_destructor() XZXX /opal/mca/base/mca_base_var.c:1859
 2 0x000000000003ec96 opal_obj_run_destructors()  XXXXXX/ompi-er2/opal/mca/base/../../../opal/class/opal_object.h:472
 3 0x000000000004136b mca_base_var_finalize()  XXXXXX/opal/mca/base/mca_base_var.c:1122
 4 0x000000000002ed5a opal_finalize_cleanup_domain()  XXXXXXXX/opal/runtime/opal_finalize_core.c:128
 5 0x000000000002eeba opal_finalize_util()  XXXXXXXX/opal/runtime/opal_finalize_core.c:143
 6 0x0000000000402121 main()  XXXXXXZ/ompi/tools/ompi_info/ompi_info.c:195
 7 0x0000000000023493 __libc_start_main()  ???:0
 8 0x00000000004014de _start()  ???:0

if one configures with --with-ucx=no on this system open mpi runs nominally with --enable-mca-dso conig option.