lightnvm: pblk: fix changing GC group list for a line

pblk_line_gc_list seems to had a bug since the introduction of pblk in
getting GC list for a line. In b20ba1bc7 while redesigning the GC
algorithm, the naming for the GC thresholds was altered, but the
values for high_thrs and mid_thrs were not. The result is that when
moving to the GC lists, the mid threshold is never evaluated.

Fixes: a4bd217b4("lightnvm: physical block device (pblk) target")
Signed-off-by: Rakesh Pandit <rakesh@tuxera.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/lightnvm/pblk-init.c

@@ -678,8 +678,8 @@ static int pblk_lines_init(struct pblk *pblk)
 	lm->blk_bitmap_len = BITS_TO_LONGS(geo->nr_luns) * sizeof(long);
 	lm->sec_bitmap_len = BITS_TO_LONGS(lm->sec_per_line) * sizeof(long);
 	lm->lun_bitmap_len = BITS_TO_LONGS(geo->nr_luns) * sizeof(long);
-	lm->high_thrs = lm->sec_per_line / 2;
-	lm->mid_thrs = lm->sec_per_line / 4;
+	lm->mid_thrs = lm->sec_per_line / 2;
+	lm->high_thrs = lm->sec_per_line / 4;
 	lm->meta_distance = (geo->nr_luns / 2) * pblk->min_write_pgs;
 
 	/* Calculate necessary pages for smeta. See comment over struct