crypto: iaa - Remove unnecessary debugfs_create_dir() error check in iaa_crypto_debugfs_init()

This patch removes the debugfs_create_dir() error checking in
iaa_crypto_debugfs_init(). Because the debugfs_create_dir() is developed
in a way that the caller can safely handle the errors that
occur during the creation of DebugFS nodes.

Signed-off-by: Minjie Du <duminjie@vivo.com>
Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>