Revert "gpu: nvgpu: Dump offending push buffer fragment"

Revert "gpu: nvgpu: Dump offending push buffer fragment"

Channel and gpfifo allocations are entirely separated from each
other, however, the code here assumes that active channel means
that the channel also has a gpfifo.

This reverts commit a24602f094380539788696d1b1567a4f4d914b17 which
added gpfifo dump. Changing debug dumping to be safe requires
refactoring the channel release code to use proper locking.

Bug 200017498
Bug 1530226

Change-Id: I2fb02542a17dd56a0a9ce732b327e34b85ade8b9
Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
(cherry picked from commit 3d37815d7660affeb9a4f23b0d17f870ed12dd33)
Reviewed-on: http://git-master/r/434053
Reviewed-by: Emad Mir <emir@nvidia.com>
Tested-by: Emad Mir <emir@nvidia.com>