x86/mm: re-indent after "re-arrange get_page_from_l<N>e() vs pv_l1tf_check_l<N>e()"

x86/mm: re-indent after "re-arrange get_page_from_l<N>e() vs pv_l1tf_check_l<N>e()"

That earlier change introduced two "else switch ()" constructs which now
get converted back to "normal" style (indentation). To limit indentation
depth, a conditional gets inverted in ptwr_emulated_update().

No functional change intended.

Requested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>