Fix diff option conflict in UI test
Trivial fix for test case `tests/run-make/rustdoc-verify-output-files`,
it's failing on MacOS, the `-u` option specifies the unified context format, while the `-q` option specifies only brief output. These two options are incompatible, since the unified context format produces a more detailed output than the brief output format.
apparently I missed some tests in the last commit. Rather than having
dozens of tests use the long version, use the short version in
`run-make` and the long version in `run-make-fulldeps` (which is now
only three tests)
