Ensure full_hex_file_path is always right

Author: chrismcg

lib/app_funcs.sh

@@ -19,17 +19,16 @@ function copy_hex() {
     hex_file=`basename ${hex_source}`
   else
     # hex file names after elixir-1.1 in the hex-<version>.ez form
-    hex_file=$(ls -t ${HOME}/.mix/archives/hex-*.ez | head -n 1)
+    full_hex_file_path=$(ls -t ${HOME}/.mix/archives/hex-*.ez | head -n 1)
 
     # For older versions of hex which have no version name in file
-    if [ -z "$hex_file" ]; then
-      hex_file="hex.ez"
+    if [ -z "$full_hex_file_path" ]; then
+      full_hex_file_path=${HOME}/.mix/archives/hex.ez
     fi
   fi
 
   cp ${HOME}/.hex/registry.ets ${build_path}/.hex/
 
-  full_hex_file_path=${HOME}/.mix/archives/${hex_file}
   output_section "Copying hex from $full_hex_file_path"
   cp $full_hex_file_path ${build_path}/.mix/archives
 }