bitbake: bitbake-layers: ensure tinfoil.shutdown() gets executed when tinfoil.prepare() fails

https://git.yoctoproject.org/poky/commit/bitbake/bin/bitbake-layers?id=f6de2b033d32c0f92f19f5a4a8c4c8874a00a8f7
erroneously moved tinfoil.prepare() out of try..finally block, where
'finally' contains a tinfoil.shutdown() call.

Without the shutdown, if there is an error in tinfoil.prepare() (such as parsing errors),
the tool locks up, as seen here:
https://valkyrie.yoctoproject.org/#/builders/71/builds/431

(Bitbake rev: 06b8a18339434be8f754e534dacb790a2c9cb91d)

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/bin/bitbake-layers

@@ -59,13 +59,13 @@ def main():
     plugins = []
     tinfoil = bb.tinfoil.Tinfoil(tracking=True)
     tinfoil.logger.setLevel(logger.getEffectiveLevel())
-    if global_args.force > 1:
-        bbpaths = []
-    else:
-        tinfoil.prepare(True)
-        bbpaths = tinfoil.config_data.getVar('BBPATH').split(':')
-    
-    try: 
+    try:
+        if global_args.force > 1:
+            bbpaths = []
+        else:
+            tinfoil.prepare(True)
+            bbpaths = tinfoil.config_data.getVar('BBPATH').split(':')
+
         for path in ([topdir] + bbpaths):
             pluginpath = os.path.join(path, 'lib', 'bblayers')
             bb.utils.load_plugins(logger, plugins, pluginpath)