[cache] Avoid unnecessary zeroing.

* src/cache/ftccmap.c (ftc_cmap_node_new): Use `FT_QNEW`.
* src/cache/ftcimage.c (FTC_INode_New): Ditto.
* src/cache/ftcsbits.c (FTC_SNode_New): Ditto.
diff --git a/src/cache/ftccmap.c b/src/cache/ftccmap.c
index 25ceff4..5ee6877 100644
--- a/src/cache/ftccmap.c
+++ b/src/cache/ftccmap.c
@@ -112,11 +112,11 @@
     FTC_CMapQuery  query  = (FTC_CMapQuery)ftcquery;
     FT_Error       error;
     FT_Memory      memory = cache->memory;
-    FTC_CMapNode   node   = NULL;
+    FTC_CMapNode   node;
     FT_UInt        nn;
 
 
-    if ( !FT_NEW( node ) )
+    if ( !FT_QNEW( node ) )
     {
       node->face_id    = query->face_id;
       node->cmap_index = query->cmap_index;
diff --git a/src/cache/ftcimage.c b/src/cache/ftcimage.c
index 344e73a..aec145c 100644
--- a/src/cache/ftcimage.c
+++ b/src/cache/ftcimage.c
@@ -61,10 +61,10 @@
   {
     FT_Memory  memory = cache->memory;
     FT_Error   error;
-    FTC_INode  inode  = NULL;
+    FTC_INode  inode;
 
 
-    if ( !FT_NEW( inode ) )
+    if ( !FT_QNEW( inode ) )
     {
       FTC_GNode         gnode  = FTC_GNODE( inode );
       FTC_Family        family = gquery->family;
diff --git a/src/cache/ftcsbits.c b/src/cache/ftcsbits.c
index a9fa1db..c36b8ef 100644
--- a/src/cache/ftcsbits.c
+++ b/src/cache/ftcsbits.c
@@ -233,7 +233,7 @@
       goto Exit;
     }
 
-    if ( !FT_NEW( snode ) )
+    if ( !FT_QNEW( snode ) )
     {
       FT_UInt  count, start;