util: storage: Add helper to determine whether storage is local

There's a lot of places where we skip doing actions based on the
locality of given storage type. The usual pattern is to skip it if:

virStorageSourceGetActualType(src) == VIR_STORAGE_TYPE_NETWORK

Add a simple helper to simplify the pattern to
virStorageSourceIsLocalStorage(src)

src/libvirt_private.syms

@@ -1922,6 +1922,7 @@ virStorageSourceClear;
 virStorageSourceFree;
 virStorageSourceGetActualType;
 virStorageSourceGetSecurityLabelDef;
+virStorageSourceIsLocalStorage;
 virStorageSourceNewFromBacking;
 virStorageSourcePoolDefFree;
 virStorageSourcePoolModeTypeFromString;

src/util/virstoragefile.c

@@ -1742,6 +1742,13 @@ virStorageSourceGetActualType(virStorageSourcePtr def)
 }
 
 
+bool
+virStorageSourceIsLocalStorage(virStorageSourcePtr src)
+{
+    return virStorageSourceGetActualType(src) != VIR_STORAGE_TYPE_NETWORK;
+}
+
+
 /**
  * virStorageSourceBackingStoreClear:
  *

src/util/virstoragefile.h

@@ -339,6 +339,7 @@ virStorageNetHostDefPtr virStorageNetHostDefCopy(size_t nhosts,
 void virStorageSourcePoolDefFree(virStorageSourcePoolDefPtr def);
 void virStorageSourceClear(virStorageSourcePtr def);
 int virStorageSourceGetActualType(virStorageSourcePtr def);
+bool virStorageSourceIsLocalStorage(virStorageSourcePtr src);
 void virStorageSourceFree(virStorageSourcePtr def);
 void virStorageSourceBackingStoreClear(virStorageSourcePtr def);
 virStorageSourcePtr virStorageSourceNewFromBacking(virStorageSourcePtr parent);