Fix bashism ( == -> = )

Author: rbalint

bin/emrk-factory-reset

@@ -43,7 +43,7 @@ fi
 echo "Do you want to make a backup copy of your config?"
 yesno
 
-if [ $? == 0 ]; then
+if [ $? = 0 ]; then
     cp $ROOT_MNT_DIR/$CONFIG $ROOT_MNT_DIR/config.boot.emrk-backup
     echo "Saved a backup copy to /config/config.boot.emrk-backup"  
 fi

bin/emrk-reinstall

@@ -118,7 +118,7 @@ mkdir -p $TMP_DIR
 while [ -z "$TAR_PATH" ]; do
     read -p "Enter EdgeOS image url: " URL
     curl -o $ROOT_MNT_DIR/tmp/edgeos.tar $URL
-    if [ $? == 0 ]; then
+    if [ $? = 0 ]; then
         TAR_PATH=$TMP_DIR/edgeos.tar
         break
     else

bin/emrk-remove-user-data

@@ -33,7 +33,7 @@ echo "Do you want to continue?"
 
 $YESNO
 
-if [ $? == 1 ]; then
+if [ $? = 1 ]; then
     exit 0
 fi