x86: coding style fixes to arch/x86/kernel/crash_dump_64.c

Fix conding style without change crash_dump_64.o

 arch/x86/kernel/crash_dump_64.o
 text    data     bss     dec     hex filename
 129       0       0     129      81 crash_dump_64.o.after
 129       0       0     129      81 crash_dump_64.o.before

md5:
885b52c1b92737e6b12e5107e90fc1f1  crash_dump_64.o.after
885b52c1b92737e6b12e5107e90fc1f1  crash_dump_64.o.before

Signed-off-by: Gustavo F. Padovan <gustavo@las.ic.unicamp.br>
Signed-off-by: Ingo Molnar <mingo@elte.hu>