tools/refresh.sh: restore BOARD_DIR when refresh with a different host

There is case as below:
When do testbuild under Linux host, such as './tools/configure.sh stmf4discovery:nsh',
arch/arm/src/board is a symlink to boards/arm/stm32/stm32f3discovery/src. Then do
'./tools/refresh.sh --silent stmf4discovery:nsh' after build, it would break the board
symlink with copydir.sh instead of link.sh since defconfig with Windows host config.
So call sethost.sh to restore BOARD_DIR. Or it results in 'make distclean' not correctly.

Signed-off-by: liuhaitao <liuhaitao@xiaomi.com>

tools/refresh.sh

@@ -235,13 +235,13 @@ for CONFIG in ${CONFIGS}; do
     # Then run oldconfig or oldefconfig
 
     if [ "X${defaults}" == "Xy" ]; then
-      if [ "X${debug}" = "Xy" ]; then
+      if [ "X${debug}" == "Xy" ]; then
         make olddefconfig V=1
       else
         make olddefconfig 1>/dev/null
       fi
     else
-      if [ "X${debug}" = "Xy" ]; then
+      if [ "X${debug}" == "Xy" ]; then
         make oldconfig V=1
       else
         make oldconfig 1>/dev/null
@@ -251,7 +251,7 @@ for CONFIG in ${CONFIGS}; do
 
   # Run savedefconfig to create the new defconfig file
 
-  if [ "X${debug}" = "Xy" ]; then
+  if [ "X${debug}" == "Xy" ]; then
     make savedefconfig V=1
   else
     make savedefconfig 1>/dev/null
@@ -285,15 +285,21 @@ for CONFIG in ${CONFIGS}; do
 
   # Restore any previous .config and Make.defs files
 
-  if [ -e SAVEconfig ]; then
-    mv SAVEconfig .config || \
-      { echo "ERROR: Failed to move SAVEconfig to .config"; exit 1; }
-  fi
-
   if [ -e SAVEMake.defs ]; then
     mv SAVEMake.defs Make.defs || \
       { echo "ERROR: Failed to move SAVEMake.defs to Make.defs"; exit 1; }
   fi
+
+  if [ -e SAVEconfig ]; then
+    mv SAVEconfig .config || \
+      { echo "ERROR: Failed to move SAVEconfig to .config"; exit 1; }
+
+    if [ "X${debug}" == "Xy" ]; then
+      ./tools/sethost.sh V=1
+    else
+      ./tools/sethost.sh 1>/dev/null
+    fi
+  fi
 done
 
 exit $diff