[MINOR] Handle fact that mv is different on linux, mac

Follow up to https://github.com/apache/spark/commit/ae853e8f3bdbd16427e6f1ffade4f63abaf74abb

 as `mv` throws an error on the Jenkins machines if source and destinations are the same.

Author: Shivaram Venkataraman <shivaram@cs.berkeley.edu>

Closes #16302 from shivaram/sparkr-no-mv-fix.

(cherry picked from commit 5a44f18a)
Signed-off-by: Shivaram Venkataraman <shivaram@cs.berkeley.edu>

dev/make-distribution.sh

@@ -228,8 +228,11 @@ if [ "$MAKE_R" == "true" ]; then
   # Install source package to get it to generate vignettes, etc.
   # Do not source the check-cran.sh - it should be run from where it is for it to set SPARK_HOME
   NO_TESTS=1 CLEAN_INSTALL=1 "$SPARK_HOME/"R/check-cran.sh
-  # Move R source package to file name matching the Spark release version.
-  mv $SPARK_HOME/R/SparkR_"$R_PACKAGE_VERSION".tar.gz $SPARK_HOME/R/SparkR_"$VERSION".tar.gz
+  # Move R source package to match the Spark release version if the versions are not the same.
+  # NOTE(shivaram): `mv` throws an error on Linux if source and destination are same file
+  if [ "$R_PACKAGE_VERSION" != "$VERSION" ]; then
+    mv $SPARK_HOME/R/SparkR_"$R_PACKAGE_VERSION".tar.gz $SPARK_HOME/R/SparkR_"$VERSION".tar.gz
+  fi
   popd > /dev/null
 else
   echo "Skipping building R source package"