target/arm_cti: fix regression from Tcl_return_values series

target/arm_cti: fix regression from Tcl_return_values series

Since commit 7f260f5009a774f2d66b5f3037f8f595c6881d4d native OpenOCD
command handlers should not directly use Jim_SetResult functions.
The Tcl result of a native command is built as concatenation of
command_print() strings and Jim_SetResult() is called after return
of the command handler.

Replace "wrong number of args" error messages (now not delivered to user)
by simply return ERROR_COMMAND_SYNTAX_ERROR

Change-Id: I40c1374a13859cefbdef68e0f1c13ab93538bd50
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: http://openocd.zylin.com/5363
Tested-by: jenkins
Reviewed-by: Tarek BOCHKATI <tarek.bouchkati@gmail.com>