Fix for transposed UpSet plot left annotation

[mriedl93]

I have noticed an issue with a specific use case of the UpSet plot.

I have tried to create an "transposed" UpSet plot with the sets in columns and the combinations in rows (i.e. t(m)). With this, I could not add a left_annotation. The error for that was

Error in ta_call[[1]] : subscript out of bounds

Fortunately, I quickly found the reason for that error and fixed it. It was in fact just a single variable name that was wrong, probably from copying it over from the right_annotation.

Here also a minimal working example for the case that caused the error:

lt = list(a = sample(letters, 5),
          b = sample(letters, 10),
          c = sample(letters, 15))
m1 = make_comb_mat(lt)

UpSet(t(m1), left_annotation = upset_left_annotation(t(m1)))