x86/mm: Untangle __change_page_attr_set_clr(.checkalias)

The .checkalias argument to __change_page_attr_set_clr() is overloaded
and serves two different purposes:

 - it inhibits the call to cpa_process_alias() -- as suggested by the
   name; however,

 - it also serves as 'primary' indicator for __change_page_attr()
   ( which in turn also serves as a recursion terminator for
     cpa_process_alias() ).

Untangle these by extending the use of CPA_NO_CHECK_ALIAS to all
callsites that currently use .checkalias=0 for this purpose.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221110125544.527267183%40infradead.org