kmap_atomic() is deprecated in favor of kmap_local_page(). Therefore,
replace kmap_atomic() with kmap_local_page() in ips_is_passthru(). In the
meantime remove an unnecessary comment, align code, and remove spaces.

kmap_atomic() is implemented like a kmap_local_page() which also disables
page-faults and preemption (the latter only for !PREEMPT_RT kernels).  The
code within the mapping/unmapping in ips_is_passthru() is already in atomic
context because of a call to local_irq_save() and kmap_local_page() can be
called in atomic context too (including interrupts).

Therefore, a mere replacement of the old API with the new one is all it is
required (i.e., there is no need to explicitly add any calls to
pagefault_disable() and/or preempt_disable()).
Suggested-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20230103173131.21259-1-fmdefrancesco@gmail.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>