ISDN: Fix data access out of array bounds
ISDN: Fix data access out of array bounds

Fix against access random data bytes outside the dev->chanmap array.
Thanks to Oliver Neukum for pointing me to this issue.

Signed-off-by: Karsten Keil <90bd3ab5dfafb0210c2bd99c94885684b79eea73@suse.de>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

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