example data object names overlap with example code

[pkimes]

The names of example data objects are too close to example object names used in vignettes of this (and other) packages. Can be confusing for users following example code (hard to distinguish objects created running examples and objects loaded as example data).

> data(package = "SummarizedBenchmark")
Data sets in package ‘SummarizedBenchmark’:

allSB (quantSB)         SummarizedBenchmark object of isoform
                        quantification results
sb                      SummarizedBenchmark example
tdat                    Example data.frame containing results for 50
                        two-sample t-tests.
truthdat (soneson2016)
                        SummarizedBenchmark example
txi (soneson2016)       SummarizedBenchmark example