phase: rename getphaserevs to loadphaserevs

phase: rename getphaserevs to loadphaserevs

This function is:
- already loading the data in place,
- used once in the code.

So we drop the return value and change the name to make this obvious. We keep
the function public because we'll have to use it in revset.

--- a/mercurial/phases.py	Wed Jun 17 16:45:25 2015 -0400
+++ b/mercurial/phases.py	Mon Jun 15 16:04:14 2015 -0700
@@ -194,7 +194,8 @@
                 for rev in repo.changelog.descendants(roots):
                     revs[rev] = phase
 
-    def getphaserevs(self, repo):
+    def loadphaserevs(self, repo):
+        """ensure phase information is loaded in the object"""
         if self._phaserevs is None:
             try:
                 if repo.ui.configbool('experimental',
@@ -205,7 +206,6 @@
                     self._phaserevs, self._phasesets = res
             except AttributeError:
                 self._computephaserevspure(repo)
-        return self._phaserevs
 
     def invalidate(self):
         self._phaserevs = None
@@ -233,7 +233,7 @@
             raise ValueError(_('cannot lookup negative revision'))
         if self._phaserevs is None or rev >= len(self._phaserevs):
             self.invalidate()
-            self._phaserevs = self.getphaserevs(repo)
+            self.loadphaserevs(repo)
         return self._phaserevs[rev]
 
     def write(self):