pds_core: make wait_context part of q_info

pds_core: make wait_context part of q_info

[ Upstream commit 3f77c3dfffc7063428b100c4945ca2a7a8680380 ]

Make the wait_context a full part of the q_info struct rather
than a stack variable that goes away after pdsc_adminq_post()
is done so that the context is still available after the wait
loop has given up.

There was a case where a slow development firmware caused
the adminq request to time out, but then later the FW finally
finished the request and sent the interrupt.  The handler tried
to complete_all() the completion context that had been created
on the stack in pdsc_adminq_post() but no longer existed.
This caused bad pointer usage, kernel crashes, and much wailing
and gnashing of teeth.

Fixes: 01ba61b55b20 ("pds_core: Add adminq processing and commands")
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20250421174606.3892-5-shannon.nelson@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>