ICU-13410 environmentTest.sh must be updated to use current paths

X-SVN-Rev: 40609
diff --git a/tools/release/c/environmentTest.sh b/tools/release/c/environmentTest.sh
index a6be63a..19b03dc 100755
--- a/tools/release/c/environmentTest.sh
+++ b/tools/release/c/environmentTest.sh
@@ -9,7 +9,7 @@
 # machine (usually Linux), and runs the existing ICU4C tests to make sure that
 # the tests pass. Not everyone is using and testing ICU4C in the en_US locale
 # with the Pacific timezone.
-top_icu_dir=../../../icu
+top_icu_dir=../../../icu4c
 release_tools_dir=../../../../tools/release/c
 cd $top_icu_dir/source/test/intltest
 $release_tools_dir/allLocaleTest.sh intltest &