[PATCH v3 2/2] hw/arm/smmu-common: Simplify smmu_find_smmu_pcibus() logic

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

The smmu_find_smmu_pcibus() function was introduced (in commit
cac994ef43b) in a code format that could return an incorrect
pointer, which was then fixed by the previous commit.
We could have avoided this by writing the if() statement
differently. Do it now, in case this function is re-used.
The code is easier to review (harder to miss bugs).

Acked-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
This patch is easier to review with 'git-diff -w' (--ignore-all-space)

v3: Fixed typo reported by Eric
---
 hw/arm/smmu-common.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/hw/arm/smmu-common.c b/hw/arm/smmu-common.c
index 67d7b2d0fd..e13a5f4a7c 100644
--- a/hw/arm/smmu-common.c
+++ b/hw/arm/smmu-common.c
@@ -290,20 +290,21 @@ inline int smmu_ptw(SMMUTransCfg *cfg, dma_addr_t iova, IOMMUAccessFlags perm,
 SMMUPciBus *smmu_find_smmu_pcibus(SMMUState *s, uint8_t bus_num)
 {
     SMMUPciBus *smmu_pci_bus = s->smmu_pcibus_by_bus_num[bus_num];
+    GHashTableIter iter;
 
-    if (!smmu_pci_bus) {
-        GHashTableIter iter;
-
-        g_hash_table_iter_init(&iter, s->smmu_pcibus_by_busptr);
-        while (g_hash_table_iter_next(&iter, NULL, (void **)&smmu_pci_bus)) {
-            if (pci_bus_num(smmu_pci_bus->bus) == bus_num) {
-                s->smmu_pcibus_by_bus_num[bus_num] = smmu_pci_bus;
-                return smmu_pci_bus;
-            }
-        }
-        smmu_pci_bus = NULL;
+    if (smmu_pci_bus) {
+        return smmu_pci_bus;
     }
-    return smmu_pci_bus;
+
+    g_hash_table_iter_init(&iter, s->smmu_pcibus_by_busptr);
+    while (g_hash_table_iter_next(&iter, NULL, (void **)&smmu_pci_bus)) {
+        if (pci_bus_num(smmu_pci_bus->bus) == bus_num) {
+            s->smmu_pcibus_by_bus_num[bus_num] = smmu_pci_bus;
+            return smmu_pci_bus;
+        }
+    }
+
+    return NULL;
 }
 
 static AddressSpace *smmu_find_add_as(PCIBus *bus, void *opaque, int devfn)
-- 
2.21.1