scripts/gdb: fix 'lx-lsmod' show the wrong size

scripts/gdb: fix 'lx-lsmod' show the wrong size

'lsmod' shows total core layout size, so we need to sum up all the
sections in core layout in gdb scripts.

/ # lsmod
kasan_test 200704 0 - Live 0xffff80007f640000

Before patch:
(gdb) lx-lsmod
Address            Module                  Size  Used by
0xffff80007f640000 kasan_test             36864  0

After patch:
(gdb) lx-lsmod
Address            Module                  Size  Used by
0xffff80007f640000 kasan_test            200704  0

Link: https://lkml.kernel.org/r/20230710092852.31049-1-Kuan-Ying.Lee@mediatek.com
Fixes: b4aff7513df3 ("scripts/gdb: use mem instead of core_layout to get the module address")
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Qun-Wei Lin <qun-wei.lin@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>