remotefilelog: remove strkwargs()

The previous commit activated previously unused code paths on
Python 3 and revealed that we were calling strkwargs() on a dict
that already had str keys. The only caller of _forceprefetch()
is _adjustlinknode() a few lines up and the static commonlogkwargs
dict features str keys.

Differential Revision: https://phab.mercurial-scm.org/D5958

hgext/remotefilelog/remotefilectx.py

@@ -15,7 +15,6 b' from mercurial import ('
     context,
     error,
     phases,
-    pycompat,
     util,
 )
 from . import shallowutil
@@ -316,7 +315,7 b' class remotefilectx(context.filectx):'
         finally:
             elapsed = time.time() - start
             repo.ui.log('linkrevfixup', logmsg + '\n', elapsed=elapsed * 1000,
-                        **pycompat.strkwargs(commonlogkwargs))
+                        **commonlogkwargs)
 
     def _verifylinknode(self, revs, linknode):
         """