Fix `test_reduce_add_coalesced ` failure (#74027)
Summary:
Recent change (https://github.com/pytorch/pytorch/pull/69751) introduced the requirement of using `.coalesce()` explicitly in the tests. Unfortunately, not all tests are run in the current CI configuration and one test failure slipped through.
Fixes https://github.com/pytorch/pytorch/issues/74015.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/74027
Reviewed By: samdow
Differential Revision: D34858112
Pulled By: mruberry
fbshipit-source-id: 8904fac5e2b5335684a21f95a22646469478eb81
(cherry picked from commit 06d6e6d2a796af0e8444f4c57841a07ec4f67c9f)
