[PATCH] Fix a bug in tstatus.exp matching tstatus output

[Yao Qi <yao@codesourcery.com>]

When running gdb.trace/tstatus.exp, we got the following output,

(gdb) tstatus
Trace stopped by a tstop command (because I can).
Collected 1 trace frames.
Trace buffer has 5242418 bytes of 5242880 bytes free (0% full).
Trace will stop if GDB disconnects.
Trace user is me me me.
Trace notes: different note.
Not looking at any trace frame.
Trace started at 572.802356 secs, stopped 0.085292 secs later.

apparently the stop reason is printed, but the test summary is

  (gdb) PASS: gdb.trace/tstatus.exp: tstatus does not report trace stop reason

after examining tstatus.exp, I find the "\\\" is missed for parentheses in
"(because I can)".  This patch adds "\\\" for them, and the test summary
becomes:

  (gdb) PASS: gdb.trace/tstatus.exp: tstatus reports trace stop reason

In gdb testsuite, both "\\\(" and "\\(" are used.  After reading
section "4.3. Backslashes" in book "Exploring Expect", I think they
are the same on effect.

gdb/testsuite:

2013-03-04  Yao Qi  <yao@codesourcery.com>

	* gdb.trace/tstatus.exp (run_trace_experiment): Add "\\\" to
	parentheses.
---
 gdb/testsuite/gdb.trace/tstatus.exp |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/gdb/testsuite/gdb.trace/tstatus.exp b/gdb/testsuite/gdb.trace/tstatus.exp
index db620d0..654b64e 100644
--- a/gdb/testsuite/gdb.trace/tstatus.exp
+++ b/gdb/testsuite/gdb.trace/tstatus.exp
@@ -99,7 +99,7 @@ proc run_trace_experiment {} {
     gdb_test_no_output "tstop because I can" "trace stopped with note"
 
     gdb_test_multiple "tstatus" "check on trace status after stop" {
-	-re "Trace stopped by a tstop command (because I can)\..*Trace will stop if GDB disconnects\.\[\r\n\]+Trace user is me me me\.\[\r\n\]+Trace notes: different note\.\[\r\n\]+Not looking at any trace frame\..*\r\n$gdb_prompt $" {
+	-re "Trace stopped by a tstop command \\\(because I can\\\)\..*Trace will stop if GDB disconnects\.\[\r\n\]+Trace user is me me me\.\[\r\n\]+Trace notes: different note\.\[\r\n\]+Not looking at any trace frame\..*\r\n$gdb_prompt $" {
 	    pass "tstatus reports trace stop reason"
 	}
 	-re "Trace stopped by a tstop command\..*\r\n$gdb_prompt $" {
-- 
1.7.7.6