refactor(quickget): special case image processing shellcheck compliant

quickget

@@ -3369,31 +3369,35 @@ function create_vm() {
         check_hash "${ISO}" "${HASH}"
     fi
 
-    if [ ${OS} == "freedos" ] && [[ ${ISO} =~ ".zip" ]]; then
-        unzip ${VM_PATH}/${ISO} -d ${VM_PATH}
-        ISO=$(ls ${VM_PATH} | grep -i '.iso')
-    fi
-
-    if [[ ${OS} == "batocera" ]] && [[ ${ISO} =~ ".gz" ]]; then
+    case "${OS}" in
+        batocera)
+            if [[ ${ISO} = *".gz"* ]]; then
                 gzip -d "${VM_PATH}/${ISO}"
                 ISO="${ISO/.gz/}"
-    fi
+            fi;;
+        dragonflybsd)
             #  Could be other OS iso files compressed with bzip2 or gzip
             #  but for now we'll keep this to know cases
-    if [[ ${OS} == "dragonflybsd" ]] && [[ ${ISO} =~ ".bz2" ]]; then
+            if [[ ${ISO} = *".bz2"* ]]; then
                 bzip2 -d  "${VM_PATH}/${ISO}"
                 ISO="${ISO/.bz2/}"
-    fi
-
-    if [[ ${OS} == "easyos" ]] && [[ ${ISO} =~ ".img" ]]; then
+            fi;;
+        easyos)
+            if [[ ${ISO} = *".img"* ]]; then
                 qemu-img convert -f raw -O qcow2 "${VM_PATH}/${ISO}" "${VM_PATH}/disk.qcow2"
                 ISO="${ISO/.img/}"
-    fi
-
-    if [ ${OS} == "reactos" ] && [[ ${ISO} =~ ".zip" ]]; then
+            fi;;
+        freedos)
+            if [[ ${ISO} = *".zip"* ]]; then
+                unzip ${VM_PATH}/${ISO} -d ${VM_PATH}
+                ISO=$(ls ${VM_PATH} | grep -i '.iso')
+            fi;;
+        reactos)
+            if [[ ${ISO} = *".zip"* ]]; then
                 unzip ${VM_PATH}/${ISO} -d ${VM_PATH}
                 ISO=$(ls ${VM_PATH} | grep -i '.iso' | grep -v '.zip')
-    fi
+            fi;;
+    esac
     make_vm_config "${ISO}"
 }