Fix some SkCodecPrintfs
Fix some SkCodecPrintfs

Silence the warning about peeking. Until we implement peeking for the
stream often used, it will always print, cluttering the logs.

Add some more information to the warning about failing to rewind.
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1564843002

Review URL: https://codereview.chromium.org/1564843002

Hikari-no-Tenshi/android_external_skia,aosp-mirror/platform_external_skia,Hikari-no-Tenshi/android_external_skia,qrealka/skia-hc,google/skia,HalCanary/skia-hc,HalCanary/skia-hc,google/skia,google/skia,google/skia,qrealka/skia-hc,qrealka/skia-hc,tmpvar/skia.cc,rubenvb/skia,tmpvar/skia.cc,Hikari-no-Tenshi/android_external_skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,qrealka/skia-hc,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,rubenvb/skia,HalCanary/skia-hc,tmpvar/skia.cc,Hikari-no-Tenshi/android_external_skia,HalCanary/skia-hc,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,qrealka/skia-hc,rubenvb/skia,tmpvar/skia.cc,qrealka/skia-hc,tmpvar/skia.cc,google/skia,rubenvb/skia,tmpvar/skia.cc,qrealka/skia-hc,tmpvar/skia.cc,aosp-mirror/platform_external_skia,HalCanary/skia-hc,tmpvar/skia.cc,google/skia,tmpvar/skia.cc,aosp-mirror/platform_external_skia,google/skia,google/skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,google/skia,rubenvb/skia,HalCanary/skia-hc,rubenvb/skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,qrealka/skia-hc,rubenvb/skia,aosp-mirror/platform_external_skia