fs/open.c: Fix W=1 kernel doc warnings

fs/open.c: In functions 'setattr_vfsuid' and 'setattr_vfsgid':
 warning: Function parameter or member 'attr' not described
 - Fix warning by removing kernel-doc for these as they are static
   inline functions and not required to be exposed via kernel-doc.

fs/open.c:
 warning: Excess function parameter 'opened' description in 'finish_open'
 warning: Excess function parameter 'cred' description in 'vfs_open'
 - Fix by removing the parameters from the kernel-doc as they are no
   longer required by the function.

Signed-off-by: Anuradha Weeraman <anuradha@debian.org>
Message-Id: <20230506182928.384105-1-anuradha@debian.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>