x86/kdump: add log before booting crash kernel

from euler inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4S9W4?from=project-issue
CVE: NA

---------------------------

Just like arm64, print "Bye!" before booting crash kernel.
Signed-off-by: NBin Wang <wangbin224@huawei.com>
Reviewed-by: Nluo chunsheng <luochunsheng@huawei.com>
Reviewed-by: NYang Jihong <yangjihong1@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/x86/kernel/machine_kexec_64.c

@@ -364,6 +364,8 @@ void machine_kexec(struct kimage *image)
 		page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page)
 						<< PAGE_SHIFT);
 
+	pr_info("Bye!\n");
+
 	/*
 	 * The segment registers are funny things, they have both a
 	 * visible and an invisible part.  Whenever the visible part is