fs/nfs: Fix used uninitialized warn in nfs4_slot_seqid_in_use()

Fix the following warn:

fs/nfs/nfs4session.c: In function ‘nfs4_slot_seqid_in_use’:
fs/nfs/nfs4session.c:203:54: warning: ‘cur_seq’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  if (nfs4_slot_get_seqid(tbl, slotid, &cur_seq) == 0 &&
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~
      cur_seq == seq_nr && test_bit(slotid, tbl->used_slots))
      ~~~~~~~~~~~~~~~~~
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/nfs4session.c

@@ -198,7 +198,7 @@ static int nfs4_slot_get_seqid(struct nfs4_slot_table  *tbl, u32 slotid,
 static bool nfs4_slot_seqid_in_use(struct nfs4_slot_table *tbl,
 		u32 slotid, u32 seq_nr)
 {
-	u32 cur_seq;
+	u32 cur_seq = 0;
 	bool ret = false;
 
 	spin_lock(&tbl->slot_tbl_lock);