Fix some doc nits

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2909)
diff --git a/util/find-doc-nits b/util/find-doc-nits
index 0b85515..537e132 100755
--- a/util/find-doc-nits
+++ b/util/find-doc-nits
@@ -96,6 +96,9 @@
         } elsif ( $line =~ /typedef.* (\S+);/ ) {
             # a simple typedef: typedef ... NAME;
             $sym = $1;
+        } elsif ( $line =~ /enum (\S*) {/ ) {
+            # an enumeration: enum ... {
+            $sym = $1;
         } elsif ( $line =~ /#define ([A-Za-z0-9_]+)/ ) {
             $sym = $1;
         } elsif ( $line =~ /([A-Za-z0-9_]+)\(/ ) {