Fix operator precedence bug and unbound variable in tfenv-version-name.sh

Fix #406: Replace undefined ${requested} variable with ${TFENV_VERSION}
in the error message on line 82. The variable was introduced in commit
3dc5819 but never existed in scope, causing an unbound variable crash
under set -u before the error message could be displayed.

Fix #431: Fix shell operator precedence in the version file read on
line 13. The original "cat ... || true | tr" meant tr only ran on the
failure path due to || binding tighter than |. Restructured to
"cat ... | tr ... || true" so carriage returns are always stripped.

Also addresses #447 (WSL carriage return symptoms) which shares the
same root cause as #431.

Author: Zordrak

lib/tfenv-version-name.sh

@@ -10,7 +10,7 @@ function tfenv-version-name() {
       && log 'debug' "TFENV_VERSION_FILE retrieved from tfenv-version-file: ${TFENV_VERSION_FILE}" \
       || log 'error' 'Failed to retrieve TFENV_VERSION_FILE from tfenv-version-file';
 
-    TFENV_VERSION="$(cat "${TFENV_VERSION_FILE}" || true | tr -d '\r')" \
+    TFENV_VERSION="$(cat "${TFENV_VERSION_FILE}" | tr -d '\r' || true)" \
       && log 'debug' "TFENV_VERSION specified in TFENV_VERSION_FILE: ${TFENV_VERSION}";
 
     TFENV_VERSION_SOURCE="${TFENV_VERSION_FILE}";
@@ -77,7 +77,7 @@ function tfenv-version-name() {
             TFENV_VERSION="${local_version}";
           fi;
       else
-        log 'error' "No versions matching '${requested}' found in remote";
+        log 'error' "No versions matching '${TFENV_VERSION}' found in remote";
       fi;
     else
       if [[ -n "${local_version}" ]]; then