x86/mce: Assign boolean values to a bool variable

Fix the following coccinelle warnings:

  ./arch/x86/kernel/cpu/mce/core.c:1765:3-20: WARNING: Assignment of 0/1 to bool variable
  ./arch/x86/kernel/cpu/mce/core.c:1584:2-9: WARNING: Assignment of 0/1 to bool variable

 [ bp: Massage commit message. ]

Reported-by: Tosk Robot <tencent_os_robot@tencent.com>
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1604654363-1463-1-git-send-email-kaixuxia@tencent.com