net, internal/poll: kernelVersion helper miscalculates minor version component

[dmitshur]

In kernelVersion, after reaching the end of the major version component, the accumulated value is used. But it isn't reset to zero after, so the minor version component computation is polluted.

This can be reproduced on the playground, see https://play.golang.org/p/U8-OWl-gzR4.

The fix is to add one line:

value = 0

Both copies of kernelVersion helper were introduced recently and can be fixed in time for Go 1.16.

CC @cuonglm, @ianlancetaylor.

[ianlancetaylor]

Thanks for noticing.

[gopherbot]

Change https://golang.org/cl/271846 mentions this issue: net, internal/poll: reset value before adding in minor kernel version