frontswap: remove frontswap_test

frontswap_test is unused now, remove it.

Link: https://lkml.kernel.org/r/20211224062246.1258487-10-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/frontswap.c b/mm/frontswap.c
index 42d554d..f51159f 100644
--- a/mm/frontswap.c
+++ b/mm/frontswap.c
@@ -179,7 +179,7 @@ void frontswap_init(unsigned type, unsigned long *map)
 		ops->init(type);
 }
 
-bool __frontswap_test(struct swap_info_struct *sis,
+static bool __frontswap_test(struct swap_info_struct *sis,
 				pgoff_t offset)
 {
 	if (sis->frontswap_map)