forcedeth: fix buffer overflow
forcedeth: fix buffer overflow

Found by manual code inspection.

Tested: compile, reboot, ethtool -d ethX

Signed-off-by: David Decotigny <4ea25430be35cce252b0a8bd038acb99e6da3664@googlers.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

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