Fix SkTextblob deserialization fuzzer issues

1)

../../src/core/SkTextBlob.cpp:778:27: runtime error: load of value 143, which is not a valid value for type 'bool'

2)

../../src/core/SkValidatingReadBuffer.cpp:208:16: runtime error: null pointer passed as argument 1, which is declared to never be null


BUG=skia:7337

Change-Id: I1df163ad378fdd2f3e4d918eb511d9f32ff41d25
Reviewed-on: https://skia-review.googlesource.com/75380
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>
1 file changed