powerpc/pseries: use kfree_sensitive() in plpks_gen_password()

password might contain private information, so better use
kfree_sensitive to free it.
In plpks_gen_password() use kfree_sensitive().
Signed-off-by: Minjie Du <duminjie@vivo.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230717092648.9752-1-duminjie@vivo.com

arch/powerpc/platforms/pseries/plpks.c

@@ -150,7 +150,7 @@ static int plpks_gen_password(void)
 		ospasswordlength = maxpwsize;
 		ospassword = kzalloc(maxpwsize, GFP_KERNEL);
 		if (!ospassword) {
-			kfree(password);
+			kfree_sensitive(password);
 			return -ENOMEM;
 		}
 		memcpy(ospassword, password, ospasswordlength);
@@ -163,7 +163,7 @@ static int plpks_gen_password(void)
 		}
 	}
 out:
-	kfree(password);
+	kfree_sensitive(password);
 
 	return pseries_status_to_err(rc);
 }