win32*.sh: cleanup dependency build dir when targetting Windows

We're using a separate dir when building Ceph dependencies for
Windows. The build script isn't entirely idempotent ATM, so the
easiest thing to do is to just cleanup this dir when rebuilding
dependencies.

If *all* dependencies have been successfully built, this step is
skipped by default.

Signed-off-by: Lucian Petrut <lpetrut@cloudbasesolutions.com>

win32_deps_build.sh

@@ -51,6 +51,11 @@ function _make() {
   make -j $NUM_WORKERS $@
 }
 
+if [[ -d $DEPS_DIR ]]; then
+    echo "Cleaning up dependency build dir: $DEPS_DIR"
+    rm -rf $DEPS_DIR
+fi
+
 mkdir -p $DEPS_DIR
 mkdir -p $depsToolsetDir
 mkdir -p $depsSrcDir