Clang warns about exceeded stack frame size

  fs/smb/client/smb2ops.c:2973:12: warning: stack frame size (1336)
  exceeds limit (1024) in 'smb2_query_reparse_point'
  [-Wframe-larger-than]

Fix this by allocating a structure that will hold most of the large
variables.
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>