mm/filemap.c: remove misleading comment

We no longer return 0 here and the comment doesn't tell us anything that
we don't already know (SIGBUS is a pretty good indicator that things
didn't work out).
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Link: http://lkml.kernel.org/r/20200529123243.20640-1-willy@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/filemap.c

@@ -2566,7 +2566,6 @@ vm_fault_t filemap_fault(struct vm_fault *vmf)
 	if (!error || error == AOP_TRUNCATED_PAGE)
 		goto retry_find;
 
-	/* Things didn't work out. Return zero to tell the mm layer so. */
 	shrink_readahead_size_eio(ra);
 	return VM_FAULT_SIGBUS;