drm/drm_exec: avoid indirect goto

drm/drm_exec: avoid indirect goto

The drm_exec component uses a variable with scope limited to the for() and
an indirect goto to allow instantiating multiple macros in the same
function.

This unfortunately doesn't work well with certain compilers when the
indirect goto can't be lowered to a direct jump.

Switch the indirect goto to a direct goto, the drawback is that we now
can't use the dma_exec_until_all_locked() macro in the same function
multiple times.

The is currently only one user of this and only as a hacky workaround
which is about to be removed.

So document that the __label__ statement should be used when the macro is
used multiple times and fix the tests and the only use case where that is
necessary.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Christian König <christian.koenig@amd.com>
Fixes: 9920249a5288 ("drm/amdgpu: convert amdgpu_vm_lock_by_pasid() to drm_exec")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202606231854.7LeCtlLe-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202606232356.gwHMAJAW-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202606240753.kYjobJVl-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202606241110.iUga5vVw-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202607031446.1PWG18mN-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202607031837.HSmBj8pr-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202607040159.GopyEswS-lkp@intel.com/
Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Link: https://lore.kernel.org/r/20260704084133.122053-1-christian.koenig@amd.com