Stop using |ERR_peek_last_error| in RSA blinding.

History has shown there are bugs in not setting the error code
appropriately, which makes any decision making based on
|ERR_peek_last_error|, etc. suspect. Also, this call was interfering
with the link-time optimizer's ability to discard the implementations of
many functions in crypto/err during dead code elimination.

Change-Id: Iba9e553bf0a72a1370ceb17ff275f5a20fca31ec
Reviewed-on: https://boringssl-review.googlesource.com/5748
Reviewed-by: Adam Langley <agl@google.com>
3 files changed