scripts/gdb: remove exception handling and refine print format

1. When we crash on a page, we want to check what happened on this
   page instead of skipping this page by try-except block.  Thus, removing
   the try-except block.

2. Remove redundant comma and print the task name properly.

Link: https://lkml.kernel.org/r/20231127070404.4192-4-Kuan-Ying.Lee@mediatek.com
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Qun-Wei Lin <qun-wei.lin@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>