Fix return type for getxattr in smack UT
Fix return type for getxattr in smack UT

Resolves: LE-7381
Change-Id: I415aca666dbf2b984a469b30109cd933d9f41bcb

legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af