Clean up crate_universe output printing

[illicitonion]

This avoids a weird double-printing of errors we used to get.

[UebelAndre]

Doesn't this make more info print? What does the output look like now?

[illicitonion]

No, crate_universe_resolver is a nice quiet binary - it doesn't print anything in the case of successful execution at standard log levels. So if RUST_LOG is set to its default info, the output looks exactly the same.

If you turn up RUST_LOG you'll get unprefixed output like:

INFO: Invocation ID: e2c06156-6684-4403-b42a-b64f112fe233
[2021-05-10T10:08:16Z DEBUG globset] glob converted to regex: Glob { glob: "src/not/a/dir/*", re: "(?-u)^src/not/a/dir/[^/]*$", opts: GlobOptions { case_insensitive: false, literal_separator: true, backslash_escape: true }, tokens: Tokens([Literal('s'), Literal('r'), Literal('c'), Literal('/'), Literal('n'), Literal('o'), Literal('t'), Literal('/'), Literal('a'), Literal('/'), Literal('d'), Literal('i'), Literal('r'), Literal('/'), ZeroOrMore]) }
[2021-05-10T10:08:16Z DEBUG globset] built glob set; 0 literals, 0 basenames, 0 extensions, 0 prefixes, 0 suffixes, 0 required extensions, 1 regexes
INFO: Analyzed target //rust/example:example (4 packages loaded, 143 targets configured).

If you get an error, you'll see output like:

INFO: Invocation ID: dccd2236-8d6e-4466-bcd6-ee8d9125b861
Error: Error parsing "/<redacted>/Cargo.toml"

Caused by:
    expected an equals, found a newline at line 12 column 9
INFO: Repository example instantiated at:
  /<redacted>/WORKSPACE:10:15: in <toplevel>
  /<redacted>/workspace.bzl:27:20: in crate_universe
Repository rule crate_universe defined at:
  /<redacted>/crate_universe/defs.bzl:152:33: in <toplevel>
ERROR: An error occurred during the fetch of repository 'example':
   Traceback (most recent call last):
	File "/<redacted>/crate_universe/defs.bzl", line 148, column 13, in _crate_universe_resolve_impl
		fail("Error resolving crate_universe deps - see above output for more information")
Error in fail: Error resolving crate_universe deps - see above output for more information
ERROR: Error fetching repository: Traceback (most recent call last):
	File "/<redacted>/crate_universe/defs.bzl", line 148, column 13, in _crate_universe_resolve_impl
		fail("Error resolving crate_universe deps - see above output for more information")
Error in fail: Error resolving crate_universe deps - see above output for more information