[R][doc] Update docs about fitting from CSR (#9818)

R-package/man/xgb.DMatrix.Rd

@@ -15,7 +15,7 @@ xgb.DMatrix(
 }
 \arguments{
 \item{data}{a \code{matrix} object (either numeric or integer), a \code{dgCMatrix} object,
-a \code{dgRMatrix} object (only when making predictions from a fitted model),
+a \code{dgRMatrix} object,
 a \code{dsparseVector} object (only when making predictions from a fitted model, will be
 interpreted as a row vector), or a character string representing a filename.}