v3 page-read: make function seek_pagemap_page can be used in dedup

Signed-off-by: Tikhomirov Pavel <snorcht@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

include/page-read.h

@@ -68,4 +68,5 @@ struct page_read {
 
 extern int open_page_read(int pid, struct page_read *);
 extern void pagemap2iovec(PagemapEntry *pe, struct iovec *iov);
+extern int seek_pagemap_page(struct page_read *pr, unsigned long vaddr, bool warn);
 #endif /* __CR_PAGE_READ_H__ */

page-read.c

@@ -83,7 +83,7 @@ static void skip_pagemap_pages(struct page_read *pr, unsigned long len)
 	pr->cvaddr += len;
 }
 
-static int seek_pagemap_page(struct page_read *pr, unsigned long vaddr, bool warn)
+int seek_pagemap_page(struct page_read *pr, unsigned long vaddr, bool warn)
 {
 	int ret;
 	struct iovec iov;