bufcache_getcleanbuf() is only used by the hibernate code and thus does
not need to grow the installation media kernels. Also, it is not used
outside of vfs_bio.c and may not deserve a public declaration either.

Index: sys/kern/vfs_bio.c
===================================================================
RCS file: /OpenBSD/src/sys/kern/vfs_bio.c,v
diff -u -p -u -p -r1.219 vfs_bio.c
--- sys/kern/vfs_bio.c	12 Jun 2026 06:34:19 -0000	1.219
+++ sys/kern/vfs_bio.c	20 Sep 2026 16:47:44 -0000
@@ -1304,6 +1304,7 @@ bufcache_adjust(void)
 		continue;
 }
 
+#ifdef HIBERNATE
 /*
  * Get a clean buffer from the cache. if "discard" is set do not promote
  * previously warm buffers as normal, because we are tossing everything
@@ -1349,6 +1350,7 @@ bufcache_getcleanbuf(int discard)
 	}
 	return bp;
 }
+#endif	/* HIBERNATE */
 
 
 void
Index: sys/sys/buf.h
===================================================================
RCS file: /OpenBSD/src/sys/sys/buf.h,v
diff -u -p -u -p -r1.123 buf.h
--- sys/sys/buf.h	3 Aug 2026 03:27:45 -0000	1.123
+++ sys/sys/buf.h	20 Sep 2026 16:47:44 -0000
@@ -260,7 +260,6 @@ struct buf *incore(struct vnode *, daddr
 void bufcache_take(struct buf *);
 void bufcache_release(struct buf *);
 
-struct buf *bufcache_getcleanbuf(int);
 struct buf *bufcache_getdirtybuf(void);
 
 /*