frontswap: remove the frontswap exports

None of the frontswap API is called from modular code.

Link: https://lkml.kernel.org/r/20211224062246.1258487-8-hch@lst.deSigned-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>

mm/frontswap.c

@@ -151,7 +151,6 @@ void frontswap_register_ops(struct frontswap_ops *ops)
 		}
 	}
 }
-EXPORT_SYMBOL(frontswap_register_ops);
 
 /*
  * Called when a swap device is swapon'd.
@@ -187,7 +186,6 @@ bool __frontswap_test(struct swap_info_struct *sis,
 		return test_bit(offset, sis->frontswap_map);
 	return false;
 }
-EXPORT_SYMBOL(__frontswap_test);
 
 static inline void __frontswap_set(struct swap_info_struct *sis,
 				   pgoff_t offset)
@@ -250,7 +248,6 @@ int __frontswap_store(struct page *page)
 
 	return ret;
 }
-EXPORT_SYMBOL(__frontswap_store);
 
 /*
  * "Get" data from frontswap associated with swaptype and offset that were
@@ -283,7 +280,6 @@ int __frontswap_load(struct page *page)
 		inc_frontswap_loads();
 	return ret;
 }
-EXPORT_SYMBOL(__frontswap_load);
 
 /*
  * Invalidate any data from frontswap associated with the specified swaptype
@@ -305,7 +301,6 @@ void __frontswap_invalidate_page(unsigned type, pgoff_t offset)
 	__frontswap_clear(sis, offset);
 	inc_frontswap_invalidates();
 }
-EXPORT_SYMBOL(__frontswap_invalidate_page);
 
 /*
  * Invalidate all data from frontswap associated with all offsets for the
@@ -327,7 +322,6 @@ void __frontswap_invalidate_area(unsigned type)
 	atomic_set(&sis->frontswap_pages, 0);
 	bitmap_zero(sis->frontswap_map, sis->max);
 }
-EXPORT_SYMBOL(__frontswap_invalidate_area);
 
 static int __init init_frontswap(void)
 {