repl: flush log to output

[ChiChou]

frida repl sometimes generates empty log file when using --output flag.

Here is the minimal case to reproduce:

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    CFRunLoopRun();
    return 0;
}

• Compile with cc main.m -o test -fmodules
• frida -f ./test -e "console.log('foo')" -o log

Log file will be empty.

---

Here is also an alternative way to fix:

- self._logfile = codecs.open(options.logfile, "w", "utf-8")
+ self._logfile = codecs.open(options.logfile, "w", "utf-8", buffering=0)

Since tracer.py is calling flush() explicitly, to keep the style consistent, this patch remains the same

frida-tools/frida_tools/tracer.py

Lines 1227 to 1236 in 233ab2b

	class OutputFile:
	def __init__(self, filename: str) -> None:
	self._fd = codecs.open(filename, "wb", "utf-8")
	def close(self) -> None:
	self._fd.close()
	def append(self, message: str) -> None:
	self._fd.write(message)
	self._fd.flush()