Merge branch 'jc/avoid-redundant-submodule-fetch'

"git fetch --recurse-submodules" from multiple remotes (either from
a remote group, or "--all") used to make one extra "git fetch" in
the submodules, which has been corrected.

* jc/avoid-redundant-submodule-fetch:
  fetch: do not run a redundant fetch from submodule

diff --cc builtin/fetch.c
Simple merge