4.6 Kdump tools fail to create vmcore-dmesg.txt on systems with 64 or more CPUs

On systems with 64 or more CPUs, the crash dump tools, included with Kdump, fail to create the vmcore-dmesg.txt file which is created with the vmcore file. This may result in a segmentation fault:

...
kdump: saving to /sysroot//var/crash/127.0.0.1-2018-05-22-12:34:45/
kdump: saving vmcore-dmesg.txt
/lib/kdump-lib-initramfs.sh: line 118:   459 Segmentation fault      
$_dmesg_collector /proc/vmcore > ${_path}/vmcore-dmesg-incomplete.txt
kdump: saving vmcore-dmesg.txt failed
kdump: saving vmcore
Copying data                                      : [100.0 %] \          
eta: 0s
kdump: saving vmcore complete 

The dmesg output can be retrieved manually by running crash against the vmcore and using the dmesg command once in the crash shell. (Bug ID 28064675)