ASoC: Intel: drop unnecessary list_empty

list_for_each_entry_safe is able to handle an empty list.
The only effect of avoiding the loop is not initializing the
index variable.
Drop list_empty tests in cases where these variables are not
used.

Note that list_for_each_entry_safe is defined in terms of
list_first_entry, which indicates that it should not be used on an
empty list.  But in list_for_each_entry_safe, the element obtained by
list_first_entry is not really accessed, only the address of its
list_head field is compared to the address of the list head, so the
list_first_entry is safe.

The semantic patch that makes this change is as follows (with another
variant for the no brace case): (http://coccinelle.lip6.fr/)

<smpl>
@@
expression x,e;
iterator name list_for_each_entry_safe;
statement S;
identifier i,j;
@@
-if (!(list_empty(x))) {
   list_for_each_entry_safe(i,j,x,...) S
- }
 ... when != i
     when != j
(
  i = e;
|
? j = e;
)
</smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Link: https://lore.kernel.org/r/1595761112-11003-2-git-send-email-Julia.Lawall@inria.fr
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 2 insertions, 3 deletions

diff --git a/sound/soc/intel/skylake/skl-topology.c b/sound/soc/intel/skylake/skl-topology.c
index b9aab47d1202..b7d2d97d12a7 100644
--- a/sound/soc/intel/skylake/skl-topology.c
+++ b/sound/soc/intel/skylake/skl-topology.c
@@ -3773,9 +3773,8 @@ void skl_tplg_exit(struct snd_soc_component *component, struct hdac_bus *bus)
 	struct skl_dev *skl = bus_to_skl(bus);
 	struct skl_pipeline *ppl, *tmp;
 
-	if (!list_empty(&skl->ppl_list))
-		list_for_each_entry_safe(ppl, tmp, &skl->ppl_list, node)
-			list_del(&ppl->node);
+	list_for_each_entry_safe(ppl, tmp, &skl->ppl_list, node)
+		list_del(&ppl->node);
 
 	/* clean up topology */
 	snd_soc_tplg_component_remove(component, SND_SOC_TPLG_INDEX_ALL);