mtd: docg3 fix inbound calculations
mtd: docg3 fix inbound calculations

The last erase block was not accessible, as the out of bound
check was incorrectly rejecting the last block.
The read/write/erase offset checks were forbidding the usage of the
last block, because of the calculation which was considering the
byte after the last instead of the last byte.

Signed-off-by: Robert Jarzmik <94b2a0a74cb42a2dd0cf1b763601af7f13907aa9@free.fr>
Signed-off-by: Artem Bityutskiy <2f96f8cd3e2780a209d0ab27d1b44624d0019d3f@linux.intel.com>
Signed-off-by: David Woodhouse <b460d66aaf00c296a3db1c1d9eeafc081d5f7d70@intel.com>

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs