Documentation: Update the default value of crashkernel low
Documentation: Update the default value of crashkernel low

In commit 94fb933 ("x86/crash: Allocate enough low memory when
crashkernel=high") the default value of crashkernel low memory
is changed to 256M. In this patch update it accordingly.

Signed-off-by: Baoquan He <1b95acc14c82271bede46a8b6a84bd6be6240a7c@redhat.com>
Signed-off-by: Jonathan Corbet <b2ce64d5587c02f12e367eac59751145a0660c51@lwn.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs