Added changelog

Author: fernandofloresg

changelogs/fragments/1794-zos_mvs_raw_stdout-replaced-by-stderr.yml

@@ -0,0 +1,5 @@
+bugfixes:
+  - zos_mvs_raw - Module would return the stderr content in stdout when verbose was true and return code was 0.
+    Fix now does not replace stdout content with stderr.
+    (https://github.com/ansible-collections/ibm_zos_core/pull/1794).
+