logit(): RFC3164 conformance for /dev/kmsg fallback

RFC3164 section 5.3 states; "a colon and a space character usually
follow the TAG".  This is also the reference format in the kernel:
https://www.kernel.org/doc/Documentation/ABI/testing/dev-kmsg

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

src/log.c

@@ -139,7 +139,7 @@ void logit(int prio, const char *fmt, ...)
 		goto done;
 	}
 
-	fprintf(fp, "<%d>finit[1]:", LOG_DAEMON | prio);
+	fprintf(fp, "<%d>finit[1]: ", LOG_DAEMON | prio);
 	vfprintf(fp, fmt, ap);
 	fclose(fp);