Removed unused parameter in ggplot_gtable docs (#2475)

* removed unused parameter in docs

* updated docs

Author: burchill

R/plot-build.r

@@ -142,7 +142,6 @@ layer_grob <- function(plot, i = 1L) {
 #'  a ggplot2 plot.
 #' @return a [gtable()] object
 #' @keywords internal
-#' @param plot plot object
 #' @param data plot data generated by [ggplot_build()]
 #' @export
 ggplot_gtable <- function(data) {