zfs_arc: remove double metric

I accidentally added prefetch_metadata_misses in 61635f3 but we
already had that metric.

Fixes #1963

diff --git a/src/zfs_arc.c b/src/zfs_arc.c
index 8261282..c7d782c 100644 (file)
--- a/src/zfs_arc.c
+++ b/src/zfs_arc.c
@@ -319,7 +319,6 @@ static int za_read (void)
        za_read_derive (ksp, "mfu_ghost_hits",           "cache_result", "mfu_ghost-hit");
        za_read_derive (ksp, "mru_hits",                 "cache_result", "mru-hit");
        za_read_derive (ksp, "mru_ghost_hits",           "cache_result", "mru_ghost-hit");
-       za_read_derive (ksp, "prefetch_metadata_misses", "cache_result", "prefetch_metadata-miss");
 
        /* Ratios */
        arc_hits   = (gauge_t) get_zfs_value(ksp, "hits");