fmt: add example for Fscanf
fmt: add example for Fscanf

Change-Id: Ia3dcb3a82e452fdcf0d087e8cd01ac01ca831c84
Reviewed-on: https://go-review.googlesource.com/132597
Reviewed-by: Joe Tsai <7277d7402195d5c2006c89f45718cf82bb3e527f@gmail.com>
Reviewed-by: Kevin Burke <685caccd7011cfe58b8f9ef79ff9dca388f03c79@inburke.com>
Run-TryBot: Joe Tsai <7277d7402195d5c2006c89f45718cf82bb3e527f@gmail.com>

CAFxX/go,akutz/go,cloudflare/go,nawawi/go,akutz/go,cloudflare/go,golang/go,golang/go,josharian/go,cloudflare/go,akutz/go,josharian/go,akutz/go,nawawi/go,cloudflare/go,josharian/go,nawawi/go,golang/go,cloudflare/go,cloudflare/go,golang/go,josharian/go,CAFxX/go,josharian/go,cloudflare/go,akutz/go,josharian/go,CAFxX/go,golang/go,CAFxX/go,josharian/go,akutz/go,golang/go,josharian/go,CAFxX/go,CAFxX/go,golang/go,nawawi/go,akutz/go,nawawi/go,akutz/go,cloudflare/go,golang/go,CAFxX/go,nawawi/go,CAFxX/go,nawawi/go,nawawi/go