HADOOP-18375. Fix failure of shelltest for hadoop_add_ldlibpath. (#4652)

(cherry picked from commit 22835be63d474ddee8d3d5d113b157d73c1341c8)

hadoop-common-project/hadoop-common/src/test/scripts/hadoop-functions_test_helper.bash

@@ -16,6 +16,7 @@
 
 setup() {
 
+  export LD_LIBRARY_PATH=""
   RELTMP="${BATS_TEST_DIRNAME}/../../../target/test-dir/bats.$$.${RANDOM}"
   mkdir -p ${RELTMP}
   TMP=$(cd -P -- "${RELTMP}" >/dev/null && pwd -P)