fellow_cache: allocate cache seglists (fcsl) by used size

src/fellow_cache.c

@@ -1884,7 +1884,6 @@ fellow_cache_seglists_load(const struct fellow_cache *fc,
 	struct buddy_off_extent next;
 	const char *err;
 	ssize_t ssz;
-	size_t sz;
 
 	CHECK_OBJ_NOTNULL(fc, FELLOW_CACHE_MAGIC);
 
@@ -1926,10 +1925,9 @@ fellow_cache_seglists_load(const struct fellow_cache *fc,
 
 		ofcsl = fcsl;
 
-		sz = fellow_cache_seglist_size(fcsl, fdsl->lsegs);
-
 		fcsl_mem = buddy_alloc1_ptr_extent_wait(fc->membuddy, FEP_META,
-		    sz, 0);
+		    fellow_cache_seglist_size(fcsl, fdsl->nsegs), 0);
+
 		if (FC_INJ || fcsl_mem.ptr == NULL) {
 			err = FC_ERRSTR("disk seglist fcsl alloc failed");
 			goto err;