Fix off-by-one issue with sector size.
Fix off-by-one issue with sector size.

wes3/incubator-mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,wes3/incubator-mynewt-core,IMGJulian/incubator-mynewt-core,andrzej-kaczmarek/incubator-mynewt-core,andrzej-kaczmarek/apache-mynewt-core,IMGJulian/incubator-mynewt-core,mlaz/mynewt-core,andrzej-kaczmarek/apache-mynewt-core,wes3/incubator-mynewt-core,wes3/incubator-mynewt-core,andrzej-kaczmarek/incubator-mynewt-core,andrzej-kaczmarek/incubator-mynewt-core,wes3/incubator-mynewt-core,andrzej-kaczmarek/apache-mynewt-core,IMGJulian/incubator-mynewt-core,andrzej-kaczmarek/apache-mynewt-core,andrzej-kaczmarek/incubator-mynewt-core,andrzej-kaczmarek/incubator-mynewt-core,mlaz/mynewt-core,IMGJulian/incubator-mynewt-core,IMGJulian/incubator-mynewt-core,mlaz/mynewt-core