Fix -Wfortify-source compiler warning

dump.cpp:448:13: error: 'snprintf' will always be truncated; specified size is 2, but format string expands to at least 3 [-Werror,-Wfortify-source]
448 |             snprintf(buf, std::size(buf) - 1, "%02x", (unsigned int)b);
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Test: presubmit
Change-Id: Ie8d459a048ad8e9ecd95ecfd0d717bd311285dad
1 file changed