fetch: stop accessing "remote" variable indirectly

fetch: stop accessing "remote" variable indirectly

Access the "remote" variable passed to the fetch_one() directly rather
than through the gtransport wrapper struct constructed in this
function for other purposes.

This makes the code more readable, as it's now obvious that the remote
struct doesn't somehow get munged by the prepare_transport() function
above, which takes the "remote" struct as an argument and constructs
the "gtransport" struct, containing among other things the "remote"
struct.

A subsequent change will copy this pattern to access a new
remote->prune_tags field, but without the use of the gtransport
variable. It's useful once that change lands to see that the two
pieces of code behave exactly the same.

This pattern of accessing the container struct was added in
737c5a9cde ("fetch: make --prune configurable", 2013-07-13) when this
code was initially introduced.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>