NFSv4/flexfiles: Remove cred local variable dependency

No-op preparation change to remove dependency on cred local
variable. Subsequent striping diff has a cred per stripe so this local
variable can't be trusted to be the same.

Signed-off-by: Jonathan Curley <jcurley@purestorage.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>

Author: Jonathan Curley

fs/nfs/flexfilelayout/flexfilelayout.c

@@ -532,10 +532,10 @@ ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
 		if (mirror != fls->mirror_array[i]) {
 			/* swap cred ptrs so free_mirror will clean up old */
 			if (lgr->range.iomode == IOMODE_READ) {
-				cred = xchg(&mirror->ro_cred, cred);
+				cred = xchg(&mirror->ro_cred, fls->mirror_array[i]->ro_cred);
 				rcu_assign_pointer(fls->mirror_array[i]->ro_cred, cred);
 			} else {
-				cred = xchg(&mirror->rw_cred, cred);
+				cred = xchg(&mirror->rw_cred, fls->mirror_array[i]->rw_cred);
 				rcu_assign_pointer(fls->mirror_array[i]->rw_cred, cred);
 			}
 			ff_layout_free_mirror(fls->mirror_array[i]);