drm/gpuvm: fix name in kernel doc of drm_gpuvm_bo_obtain_locked()

drm/gpuvm: fix name in kernel doc of drm_gpuvm_bo_obtain_locked()

When renaming this function, the name in the docs was not updated. This
causes a KernelDoc warning. Thus, fix it.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202601091113.0b0WuRML-lkp@intel.com/
Fixes: 9bf4ca1e699c ("drm/gpuvm: drm_gpuvm_bo_obtain() requires lock and staged mode")
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260109082019.3999814-1-aliceryhl@google.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>