Fix awk substr invocation in libgo buildsyste

[choeger]

The awk script used a zero-based index which worked on surprisingly
many plattforms. According to the man page, however, the function
expects one-based indexing.

For reference see this bug in the go git repository:

golang/go#45843

Signed-off-by: Christoph Höger choeger@umpa-net.de

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[choeger]

@googlebot I signed it!

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Message from Ian Lance Taylor:

Patch Set 1:

(3 comments)

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Message from Than McIntosh:

Patch Set 1: Trust+1

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