security: Silence shadow warning

Renaming an unused formal parameter in the static inline function
security_inode_init_security eliminates many W=2 warnings.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>