cifs: get rid of dup length check in parse_reparse_point()

smb2_compound_op(SMB2_OP_GET_REPARSE) already checks if ioctl response
has a valid reparse data buffer's length, so there's no need to check
it again in parse_reparse_point().

In order to get rid of duplicate check, validate reparse data buffer's
length also in cifs_query_reparse_point().

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>