program: do not poll target after reset run

Disable polling the target before we issue a 'reset run'. This stops errors or
warnings if the target disables the SWD or JTAG interface as part of the
application code.

Change-Id: I5019dffdad41a8e210003ece1caf89069ee0f223
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/1331
Tested-by: jenkins