Merge pull request #321 from alex/docstring-cleanup

Clean up some docstrings
diff --git a/cryptography/hazmat/backends/openssl/asn1.py b/cryptography/hazmat/backends/openssl/asn1.py
index 719a523..c752e68 100644
--- a/cryptography/hazmat/backends/openssl/asn1.py
+++ b/cryptography/hazmat/backends/openssl/asn1.py
@@ -41,7 +41,7 @@
 typedef struct {
     ...;
 } ASN1_TIME;
-typedef const ASN1_ITEM ASN1_ITEM_EXP;
+typedef ... ASN1_ITEM_EXP;
 
 typedef ... ASN1_UTCTIME;
 
@@ -102,7 +102,7 @@
 
 MACROS = """
 ASN1_TIME *M_ASN1_TIME_dup(void *);
-ASN1_ITEM *ASN1_ITEM_ptr(ASN1_ITEM *);
+ASN1_ITEM *ASN1_ITEM_ptr(ASN1_ITEM_EXP *);
 
 /* These aren't macros these arguments are all const X on openssl > 1.0.x */