tests: make scriptlive output more portable

Signed-off-by: Karel Zak <kzak@redhat.com>

tests/expected/script/replay-live

@@ -1,7 +1,7 @@
 >>> scriptlive: Starting your typescript execution by sh --posix.
 echo "result is $(($NUMBER + 1))"
-$ echo "result is $(($NUMBER + 1))"
+prompt> echo "result is $(($NUMBER + 1))"
 result is 124
-$ exit
+prompt> exit
 
 >>> scriptlive: done.

tests/ts/script/replay

@@ -91,7 +91,7 @@ NUMBER=123 $TS_CMD_SCRIPTLIVE \
 	--command 'sh --posix' \
 	--log-in "$LOG_IN_FILE" \
 	--log-timing "$TIMING_FILE" >> $TS_OUTPUT 2>> $TS_ERRLOG
-sed -i 's/sh-[[:alnum:]\.]*//g' $TS_OUTPUT
+sed -i 's/sh-[[:alnum:]\.\$\#]*/prompt>/g' $TS_OUTPUT
 ts_finalize_subtest
 
 ts_finalize