Stop using skjpeg_error_mgr in YuvToJpegEncoder

Bug: None
Test: compile

skjpeg_error_mgr is only different from the standard one in that it
includes a jmp_buf. A recent change to skjpeg_error_mgr stores a stack
of jmp_bufs (see https://skia-review.googlesource.com/c/skia/+/79241).
This complexity is unnecessary for YuvToJpegEncoder, which only contains
a single method with libjpeg calls (which might call longjmp). Simplify
this code by placing the jmp_buf on the stack. This fixes the Skia to
Android roll, which includes the above Skia change.

Change-Id: If9a33ed10ea60131906a632a7030e0b69a21f4ea