x86/mce: Correct the detection of invalid notifier priorities

Commit

  c9c6d216 ("x86/mce: Rename "first" function as "early"")

changed the enumeration of MCE notifier priorities. Correct the check
for notifier priorities to cover the new range.

 [ bp: Rewrite commit message, remove superfluous brackets in
   conditional. ]

Fixes: c9c6d216

 ("x86/mce: Rename "first" function as "early"")
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201106141216.2062-2-thunder.leizhen@huawei.com