wasm: build: fix vlc tools PATH setting

Previously:
- $PATH was set incorrectly to wasm-emscripten/bin
  which is supposed to be wasm-emscripten/build/bin

- $PATH was updated after making the tools

Hence,
 - The tools would be rebuilt every time build script is run.

 - The setting of PATH variable would do nothing anyway even
   if it was correct, as correct PATH is going to be set by the
   configure script later anyway.

This patch will repurpose the line to avoid rebuilding of already
built tools.

extras/package/wasm-emscripten/build.sh

@@ -98,6 +98,9 @@ cd "$OLD_PWD"
 diagnostic "vlc sources path: "
 echo "$VLC_SRCPATH";
 
+# update PATH to include vlc tools
+export PATH=$VLC_SRCPATH/extras/tools/build/bin:$PATH
+
 diagnostic "vlc tools: bootstrap"
 cd "$VLC_SRCPATH"/extras/tools
 
@@ -111,9 +114,6 @@ fi
 diagnostic "vlc tools: make"
 make
 
-# update the PATH
-export PATH=$VLC_SRCPATH/extras/tools/bin:$PATH
-
 diagnostic "sdk tests: checking if autoconf supports emscripten"
 # https://code.videolan.org/-/snippets/1283
 for file in /usr/share/automake-*