RFA/testsuite: Fix `array unset' goof

[Daniel Jacobowitz <drow@mvista.com>]

I fixed linux-dp.exp to use 'array unset seen' instead of
'array set seen {}' (which doesn't do anything if seen already exists). 
Unfortunately, array unset only appeared in Tcl 8.2.3.  If you use DejaGNU
with system expect/tcl, you're likely to get an older version.  This uses
'array set seen {}' followed by 'unset seen', which should work in any Tcl
version.

OK?

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer

2002-04-15  Daniel Jacobowitz  <drow@mvista.com>

	* gdb.threads/linux-dp.exp: Use 'unset' instead of 'array unset'.

Index: gdb.threads/linux-dp.exp
===================================================================
RCS file: /cvs/src/src/gdb/testsuite/gdb.threads/linux-dp.exp,v
retrieving revision 1.6
diff -u -p -r1.6 linux-dp.exp
--- gdb.threads/linux-dp.exp	31 Jan 2002 05:08:41 -0000	1.6
+++ gdb.threads/linux-dp.exp	15 Apr 2002 21:37:19 -0000
@@ -214,7 +214,8 @@ proc check_philosopher_stack {thread see
 }
 
 set any_interesting 0
-array unset seen
+array set seen {}
+unset seen
 for {set i 1} {$i <= 7} {incr i} {
     if [check_philosopher_stack $i seen] {
 	set any_interesting 1