smack: always "instantiate" inode in smack_inode_init_security()

smack: always "instantiate" inode in smack_inode_init_security()

If memory allocation for the SMACK64TRANSMUTE
xattr value fails in smack_inode_init_security(),
the SMK_INODE_INSTANT flag is not set in
(struct inode_smack *issp)->smk_flags,
leaving the inode as not "instantiated".

It does not matter if fs frees the inode
after failed smack_inode_init_security() call,
but there is no guarantee for this.

To be safe, mark the inode as "instantiated",
even if allocation of xattr values fails.

Signed-off-by: Konstantin Andreev <andreev@swemel.ru>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>