ssh: Consistent error handling in examples
ssh: Consistent error handling in examples

After discussion around an example SFTP implementation:
https://github.com/pkg/sftp/pull/54
it has been suggested that errors should be handled using
log.Fatal rather than panic, and that the actual underlying error
should also be logged. In the existing SSH examples there
are several different styles of error handling using both panic
and log.Fatalf.

This patch uses log.Fatal consistently for all of these cases.

Change-Id: I2cebfae1821530dc3c5bbc46d451fe026bed582f
Reviewed-on: https://go-review.googlesource.com/16736
Reviewed-by: Russ Cox <5ad239cb8a44f659eaaee0aa1ea5b94947abe557@golang.org>

ScriptRock/crypto,golang/crypto,golang/crypto,ScriptRock/crypto,golang/crypto