common/logger: quiet console output to Warn (keep Info in files)

Daemons log via OutputBuilder::stderr() at output_level, which shares the
interactive console/login VT. At Info they spam routine chatter (cpufreqd,
thermald, i2c-hidd, ...) over the login prompt as boot continues in
parallel with getty. Drop the console filter to Warn; full Info logs are
still written to per-daemon log files (file_level), and a bootloader env
var can raise it for debugging.

drivers/common/src/logger.rs

@@ -3,9 +3,15 @@ use std::str::FromStr;
 use libredox::{flag, Fd};
 use redox_log::{OutputBuilder, RedoxLogger};
 
-/// Get the log verbosity for the output level.
+/// Get the log verbosity for the interactive console (stderr) output level.
+///
+/// Kept at `Warn` so daemons do not spam the shared console/login VT with
+/// routine INFO chatter after the login prompt appears (boot continues in
+/// parallel with getty). Full INFO-level logs are still written to each
+/// daemon's log files via [`file_level`]. A per-daemon bootloader env var
+/// (see `read_bootloader_log_level_env`) can still raise this when debugging.
 pub fn output_level() -> log::LevelFilter {
-    log::LevelFilter::Info
+    log::LevelFilter::Warn
 }
 
 /// Get the log verbosity for the file level.