staging: most: return error value

On error we were returning retval, but retval is not having the error
value. We will get the error value using PTR_ERR.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed