tcl: [3/3] prepare for jimtcl 0.81 'expr' syntax change

Jimtcl commit 1843b79a03dd ("expr: TIP 526, only support a single
arg") drops the support for multi-argument syntax for the TCL
command 'expr'.

Fix manually the remaining lines that don't match simple patterns
and would require dedicated boring scripting.
Remove the 'expr' command where appropriate.

Change-Id: Ia75210c8447f88d38515addab4a836af9103096d
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/6161
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>

tcl/target/bluenrg-x.cfg

@@ -65,7 +65,7 @@ $_TARGETNAME configure -event resumed {
     global WDOG_VALUE_SET
     set _JTAG_IDCODE [mrw 0x40000004]
     if {$_JTAG_IDCODE != 0x0201E041} {
-        if [expr $WDOG_VALUE_SET] {
+        if {$WDOG_VALUE_SET} {
             # Restore watchdog enable value after resume. Only Bluenrg-1/2
             mww 0x40700008 $WDOG_VALUE
             set WDOG_VALUE_SET 0