NFSD: Fix crash in nfsd4_read_release()

jira VULN-161290
cve CVE-2025-40324
commit-author Chuck Lever <chuck.lever@oracle.com>
commit abb1f08

When tracing is enabled, the trace_nfsd_read_done trace point
crashes during the pynfs read.testNoFh test.

Fixes: 15a8b55 ("nfsd: call op_release, even when op_func returns an error")
	Cc: stable@vger.kernel.org
	Reviewed-by: Jeff Layton <jlayton@kernel.org>
	Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
(cherry picked from commit abb1f08)
	Signed-off-by: Marcin Wcisło <marcin.wcislo@conclusive.pl>

Author: pvts-mat

fs/nfsd/nfs4proc.c

@@ -961,10 +961,11 @@ nfsd4_read(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 static void
 nfsd4_read_release(union nfsd4_op_u *u)
 {
-	if (u->read.rd_nf)
+	if (u->read.rd_nf) {
+		trace_nfsd_read_done(u->read.rd_rqstp, u->read.rd_fhp,
+				     u->read.rd_offset, u->read.rd_length);
 		nfsd_file_put(u->read.rd_nf);
-	trace_nfsd_read_done(u->read.rd_rqstp, u->read.rd_fhp,
-			     u->read.rd_offset, u->read.rd_length);
+	}
 }
 
 static __be32