mm/readahead: pass a file_ra_state into force_page_cache_ra

mm/readahead: pass a file_ra_state into force_page_cache_ra

The file_ra_state being passed into page_cache_sync_readahead() was being
ignored in favour of using the one embedded in the struct file.  The only
caller for which this makes a difference is the fsverity code if the file
has been marked as POSIX_FADV_RANDOM, but it's confusing and worth fixing.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric Biggers <ebiggers@google.com>
Link: https://lkml.kernel.org/r/20200903140844.14194-10-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>