kdump: add missing wc in crashcore rootfs

Tested: May 04 14:01:15 dddhg22-nfd01.prod.google.com gbmc-dump-ramoops.sh[434]: The dumpfile is saved to STDOUT.
May 04 14:01:15 dddhg22-nfd01.prod.google.com gbmc-dump-ramoops.sh[434]: makedumpfile Completed.
May 04 14:01:15 dddhg22-nfd01.prod.google.com gbmc-dump-ramoops.sh[434]: 51609+0 records in
May 04 14:01:15 dddhg22-nfd01.prod.google.com gbmc-dump-ramoops.sh[434]: 51609+0 records out
May 04 14:01:16 dddhg22-nfd01.prod.google.com gbmc-dump-ramoops.sh[514]: 11+0 records in
May 04 14:01:16 dddhg22-nfd01.prod.google.com gbmc-dump-ramoops.sh[514]: 11+0 records out
May 04 14:01:29 dddhg22-nfd01.prod.google.com gbmc-dump-ramoops.sh[515]: 407+1 records in
May 04 14:01:29 dddhg22-nfd01.prod.google.com gbmc-dump-ramoops.sh[515]: 407+1 records out
May 04 14:01:29 dddhg22-nfd01.prod.google.com gbmc-dump-ramoops.sh[516]: The dumpfile is saved to /run/log/kdump/kcore-2026_05_04_14_01_16.

Platforms-Affected: All
Google-Bug-Id: 507762548
Fusion-Link: fusion2 N/A
Change-Id: I9ef70009f353f80e3ba6d730bdb10aa87080dd73
Signed-off-by: Yuxiao Zhang <yuxiaozhang@google.com>