misc: msp430: properly set error code for BREATH ioctl

A user's BREATH vote request can not fail so set the error code to
success.

Change-Id: Icffe6b364633359afd2dc6f4df9f27e97df19245
Signed-off-by: Jared Suttles <jsuttles@motorola.com>
Signed-off-by: Joe Swantek <w98568@motorola.com>
Reviewed-on: http://gerrit.pcs.mot.com/600402
Tested-by: Jira Key <jirakey@motorola.com>
Reviewed-by: Patrick Auchter <auchter@motorola.com>
Reviewed-by: Christian Flowers <flowers@motorola.com>
Reviewed-by: Joseph Swantek <jswantek@motorola.com>
Reviewed-by: Fred Fettinger <fettinge@motorola.com>
Reviewed-by: Stephen Rossbach <rossbach@motorola.com>
SLTApproved: Stephen Rossbach <rossbach@motorola.com>
Submit-Approved: Jira Key <jirakey@motorola.com>