SUNRPC: Fix up an error return value in gss_import_sec_context_kerberos()

If the context allocation fails, the function currently returns a random
error code, since the variable 'p' still points to a valid memory location.

Ensure that it returns ENOMEM...

Cc: stable@kernel.org
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

net/sunrpc/auth_gss/gss_krb5_mech.c

@@ -131,8 +131,10 @@ gss_import_sec_context_kerberos(const void *p,
 	struct	krb5_ctx *ctx;
 	int tmp;
 
-	if (!(ctx = kzalloc(sizeof(*ctx), GFP_NOFS)))
+	if (!(ctx = kzalloc(sizeof(*ctx), GFP_NOFS))) {
+		p = ERR_PTR(-ENOMEM);
 		goto out_err;
+	}
 
 	p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate));
 	if (IS_ERR(p))