pNFS/flexfiles: Fix an Oopsable typo in ff_mirror_match_fh()

Jeff reports seeing an Oops in ff_layout_alloc_lseg. Turns out
copy+paste has played cruel tricks on a nested loop.
Reported-by: NJeff Layton <jeff.layton@primarydata.com>
Cc: stable@vger.kernel.org # 4.3+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/flexfilelayout/flexfilelayout.c

@@ -145,7 +145,7 @@ static bool ff_mirror_match_fh(const struct nfs4_ff_layout_mirror *m1,
 		return false;
 	for (i = 0; i < m1->fh_versions_cnt; i++) {
 		bool found_fh = false;
-		for (j = 0; j < m2->fh_versions_cnt; i++) {
+		for (j = 0; j < m2->fh_versions_cnt; j++) {
 			if (nfs_compare_fh(&m1->fh_versions[i],
 					&m2->fh_versions[j]) == 0) {
 				found_fh = true;