Rename c to ctx for Context
Rename c to ctx for Context

Bug: 1086813
Change-Id: Ifdf569a24491826e9a96d99cc25b8743da99e20a
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-go/+/2217694
Commit-Queue: Ye Kuang <1cd89f22f3967fc3dcb883b53940be4b98ec483f@google.com>
Commit-Queue: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>
Auto-Submit: Ye Kuang <1cd89f22f3967fc3dcb883b53940be4b98ec483f@google.com>
Reviewed-by: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go