filemap: convert filemap_range_has_writeback() to use folios

Removes 3 calls to compound_head().

Link: https://lkml.kernel.org/r/20220905214557.868606-1-vishal.moola@gmail.com


Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>