util/log: Rename qemu_logfile_mutex to global_mutex

Rename to emphasize this covers the file-scope global variables.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-35-richard.henderson@linaro.org>
1 file changed