tests: storagetest: Unify and reformat storage chain format string

All the fields crammed into two lines weren't easy to parse by human
eyes. Split up the format string into lines and put it into a central
variable so that changes in two places aren't necessary.

tests/virstoragetest.c

@@ -312,6 +312,18 @@ struct testChainData
     unsigned int flags;
 };
 
+
+static const char testStorageChainFormat[] =
+    "store: %s\n"
+    "backingStoreRaw: %s\n"
+    "capacity: %lld\n"
+    "encryption: %d\n"
+    "relPath:%s\n"
+    "path:%s\n"
+    "relDir:%s\n"
+    "type:%d\n"
+    "format:%d\n";
+
 static int
 testStorageChain(const void *args)
 {
@@ -373,8 +385,7 @@ testStorageChain(const void *args)
         expRelDir = isAbs ? data->files[i]->relDirAbs
             : data->files[i]->relDirRel;
         if (virAsprintf(&expect,
-                        "store:%s\nraw:%s\nother:%lld %d\n"
-                        "relPath:%s\npath:%s\nrelDir:%s\ntype:%d %d\n",
+                        testStorageChainFormat,
                         NULLSTR(data->files[i]->expBackingStore),
                         NULLSTR(data->files[i]->expBackingStoreRaw),
                         data->files[i]->expCapacity,
@@ -385,15 +396,16 @@ testStorageChain(const void *args)
                         data->files[i]->type,
                         data->files[i]->format) < 0 ||
             virAsprintf(&actual,
-                        "store:%s\nraw:%s\nother:%lld %d\n"
-                        "relPath:%s\npath:%s\nrelDir:%s\ntype:%d %d\n",
+                        testStorageChainFormat,
                         NULLSTR(elt->backingStore ? elt->backingStore->path : NULL),
                         NULLSTR(elt->backingStoreRaw),
-                        elt->capacity, !!elt->encryption,
+                        elt->capacity,
+                        !!elt->encryption,
                         NULLSTR(elt->relPath),
                         NULLSTR(elt->path),
                         NULLSTR(elt->relDir),
-                        elt->type, elt->format) < 0) {
+                        elt->type,
+                        elt->format) < 0) {
             VIR_FREE(expect);
             VIR_FREE(actual);
             goto cleanup;