[S390] Add VMCOREINFO_SYMBOL(high_memory) to vmcoreinfo

Currently the vmalloc_start address (or better end of real memory) for s390x
is obtained by makedumpfile using vmlist.addr symbol, which is not correct.
The correct vmalloc_start address can be obtained using 'high_memory' symbol.

This patch adds the high_memory symbol to vmcoreinfo.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/machine_kexec.c

@@ -208,6 +208,7 @@ void machine_kexec_cleanup(struct kimage *image)
 void arch_crash_save_vmcoreinfo(void)
 {
 	VMCOREINFO_SYMBOL(lowcore_ptr);
+	VMCOREINFO_SYMBOL(high_memory);
 	VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
 }