Fix a few incorrectly checked [io_]remap_pfn_range() calls

Fix a few incorrectly checked [io_]remap_pfn_range() calls

Nico Golde reports a few straggling uses of [io_]remap_pfn_range() that
really should use the vm_iomap_memory() helper.  This trivially converts
two of them to the helper, and comments about why the third one really
needs to continue to use remap_pfn_range(), and adds the missing size
check.

Reported-by: Nico Golde <[email protected]>
Cc: [email protected]
Signed-off-by: Linus Torvalds <[email protected].