staging/lustre/gss: fix few issues found by Klocwork Insight tool

Array 'message_buf' of size 500 may use index value(s) -1

Object 'enc_key.data' was freed at line 164 after being freed
by calling 'free' at line 150. Also there are 3 similar errors
on line(s) 164.

Suspicious dereference of pointer 'vmsg' before NULL check at
line 187. Also there are 2 similar errors on line(s) 196, 205.

Suspicious dereference of pointer 'rmsg' before NULL check at
line 191. Also there are 2 similar errors on line(s) 200, 209.
Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-on: http://review.whamcloud.com/9274
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4629Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/ptlrpc/gss/gss_bulk.c

@@ -176,31 +176,31 @@ int gss_cli_ctx_unwrap_bulk(struct ptlrpc_cli_ctx *ctx,
 	switch (SPTLRPC_FLVR_SVC(req->rq_flvr.sf_rpc)) {
 	case SPTLRPC_SVC_NULL:
 		vmsg = req->rq_repdata;
+		LASSERT(vmsg != NULL && vmsg->lm_bufcount >= 3);
 		voff = vmsg->lm_bufcount - 1;
-		LASSERT(vmsg && vmsg->lm_bufcount >= 3);
 
 		rmsg = req->rq_reqbuf;
+		LASSERT(rmsg != NULL && rmsg->lm_bufcount >= 3);
 		roff = rmsg->lm_bufcount - 1; /* last segment */
-		LASSERT(rmsg && rmsg->lm_bufcount >= 3);
 		break;
 	case SPTLRPC_SVC_AUTH:
 	case SPTLRPC_SVC_INTG:
 		vmsg = req->rq_repdata;
+		LASSERT(vmsg != NULL && vmsg->lm_bufcount >= 4);
 		voff = vmsg->lm_bufcount - 2;
-		LASSERT(vmsg && vmsg->lm_bufcount >= 4);
 
 		rmsg = req->rq_reqbuf;
+		LASSERT(rmsg != NULL && rmsg->lm_bufcount >= 4);
 		roff = rmsg->lm_bufcount - 2; /* second last segment */
-		LASSERT(rmsg && rmsg->lm_bufcount >= 4);
 		break;
 	case SPTLRPC_SVC_PRIV:
 		vmsg = req->rq_repdata;
+		LASSERT(vmsg != NULL && vmsg->lm_bufcount >= 2);
 		voff = vmsg->lm_bufcount - 1;
-		LASSERT(vmsg && vmsg->lm_bufcount >= 2);
 
 		rmsg = req->rq_clrbuf;
+		LASSERT(rmsg != NULL && rmsg->lm_bufcount >= 2);
 		roff = rmsg->lm_bufcount - 1; /* last segment */
-		LASSERT(rmsg && rmsg->lm_bufcount >= 2);
 		break;
 	default:
 		LBUG();