[PATCH] USB: Buffer overflow patch for Yealink driver

Just a small patch that fixes a small parameter validation bug.

  drivers/usb/input/map_to_7segment.h:
    This patch fixes the broken parameter validation in the char to seg7
    conversion. This could cause out-of-bounds memory references.

  MAINTAINERS:
    Yealink maintainer info now in sorted order.

  Documentation/input/yealink.txt:
    Added a Q&A section that answers some common questions.

Signed-off-by: Henk <Henk.Vergonet@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

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