There is a code path starting from trace2_def_param_fl() that eventually
calls current_config_scope(), and thus it needs to have "kvi" plumbed
through it. Additional plumbing is also needed to get "kvi" to
trace2_def_param_fl(), which gets called by two code paths:
- Through tr2_cfg_cb(), which is a config callback, so it trivially
receives "kvi" via the "struct config_context ctx" parameter.
- Through tr2_list_env_vars_fl(), which is a high level function that
lists environment variables for tracing. This has been secretly
behaving like git_config_from_parameters() (in that it parses config
from environment variables/the CLI), but does not set config source
information.
Teach tr2_list_env_vars_fl() to be well-behaved by using
kvi_from_param(), which is used elsewhere for CLI/environment
variable-based config.
As a result, current_config_scope() has no more callers, so remove it.
Signed-off-by: Glen Choo <chooglen@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>