verify: rename "hasmanifest" variable for source code readability

Before this patch, there are two ambiguous variables: "havemf" and
"hasmanifest".

"havemf" means whether there are any "manifest" entries.

"hasmanifest" means whether there are any "changelog" entries
referring to "manifest" entry.

This patch renames from "hasmanifest" to "refersmf" to clear
difference from "havemf".

mercurial/verify.py

@@ -120,7 +120,7 b' def _verify(repo):'
     havemf = len(mf) > 0
 
     ui.status(_("checking changesets\n"))
-    hasmanifest = False
+    refersmf = False
     seen = {}
     checklog(cl, "changelog", 0)
     total = len(repo)
@@ -133,17 +133,17 b' def _verify(repo):'
             changes = cl.read(n)
             if changes[0] != nullid:
                 mflinkrevs.setdefault(changes[0], []).append(i)
-                hasmanifest = True
+                refersmf = True
             for f in changes[3]:
                 filelinkrevs.setdefault(f, []).append(i)
         except Exception, inst:
-            hasmanifest = True
+            refersmf = True
             exc(i, _("unpacking changeset %s") % short(n), inst)
     ui.progress(_('checking'), None)
 
     ui.status(_("checking manifests\n"))
     seen = {}
-    if hasmanifest:
+    if refersmf:
         # Do not check manifest if there are only changelog entries with
         # null manifests.
         checklog(mf, "manifest", 0)