libbrillo: Log Cleanup

1)Print curl request log only for failure case
2)Removed excess log

BUG=b:65480079
TEST=cros_workon_make --test --board=gale libbrillo

Change-Id: I7e9ef0fb43cb97506043d1c1e2b324facc132a85
Reviewed-on: https://chromium-review.googlesource.com/716437
Commit-Ready: jr.shashidhar jr.shashidhar <jr.shashidhar@globaledgesoftware.corp-partner.google.com>
Tested-by: jr.shashidhar jr.shashidhar <jr.shashidhar@globaledgesoftware.corp-partner.google.com>
Reviewed-by: Julan Hsu <julanhsu@google.com>
1 file changed