revset: fix documentation for 'remote()' predicate
current documentation for 'remote()' predicate is wrong about
specification of parameters.
there are 3 patterns:
# of
param: id: remote:
- 0 current branch "defult" remote
- 1 specified "defult" remote
- 2 specified specified
revset: fix 'remote()' failure when remote repo has more revs than local
current 'remote()' implementation uses 'r' variable, even if it is not
initialized when 'if n in repo' is not true.
this causes unexpected exception.