NFS4: Remove unneeded semicolon

Fixes coccicheck warning:

fs/nfs/nfs4state.c:1138:2-3: Unneeded semicolon
fs/nfs/nfs4proc.c:6862:2-3: Unneeded semicolon
fs/nfs/nfs4proc.c:8629:2-3: Unneeded semicolon

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>