templater: make get(dict, key) return a single value

This is necessary to obtain a _hybrid object from a dict. If get() yields
a value, it would be stringified.

I see no benefit to make get() lazy, so this patch just changes "yield" to
"return".

mercurial/templater.py

@@ -432,7 +432,7 b' def get(context, mapping, args):'
         raise error.ParseError(_("get() expects a dict as first argument"))
 
     key = args[1][0](context, mapping, args[1][1])
-    yield dictarg.get(key)
+    return dictarg.get(key)
 
 def if_(context, mapping, args):
     """:if(expr, then[, else]): Conditionally execute based on the result of