The i2d_X509() function can return a negative value on error. Therefore
we should make sure we check it.
Issue reported by Yuan Jochen Kang.
(Imported from upstream's 8f43c80bfa
)
Change-Id: If247d5bf1d792eb7c6dc179b606ed21ea0ccdbb8
Reviewed-on: https://boringssl-review.googlesource.com/7743
Reviewed-by: David Benjamin <davidben@google.com>
kris/onging/CECPQ3_patch15