Rename LOG_ERROR to RTC_LOG_ERROR

Use the RTC-prefixed error logging macro name and update call sites.

The LOG_ERROR macro was introduced in https://webrtc-review.googlesource.com/c/src/+/433760 as part of the WebRTC API layer. The name is quite generic, and has high chances of collision with others when the header is leaked / included with other libraries.

Would be good to rename to something more specific, like RTC_LOG_ERROR or similar.

Bug: webrtc:517208673
Change-Id: I489af1d968c3c251b7094f27468e2c4a07de7d80
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/476520
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org>
Commit-Queue: Boris Tsirkin <btsirkin@meta.com>
Cr-Commit-Position: refs/heads/main@{#47854}