examples: error messages are not capitalized.
examples: error messages are not capitalized.

* examples/lock.lua: Don't capitalize error messages.
Discovered by 'make syntax-check'

Signed-off-by: Gary V. Vaughan <f9023000f29773649f3850298becb9544b5fd6a9@gnu.org>

zevv/luaposix,jimmyharris/luaposix,ardje/luaposix,zevv/luaposix,snegovick/luaposix,luaposix/luaposix,jimmyharris/luaposix,rrthomas/luaposix,rrthomas/luaposix,snegovick/luaposix,ardje/luaposix