Fix more OCSP_resp_get0_signer() nits
Fix a typo for "retrieve" and some indentation.
@@ -80,7 +80,7 @@ single response B<bs>.
OCSP_resp_get0_certs() returns any certificates included in B<bs>.
-OCSP_resp_get0_signer() attempts to retrive the certificate that directly
+OCSP_resp_get0_signer() attempts to retrieve the certificate that directly
signed B<bs>. The OCSP protocol does not require that this certificate
is included in the B<certs> field of the response, so additional certificates
can be supplied in B<extra_certs> if the certificates that may have
