12813: Uninitialized pointer read

string_values2keys (plugins/syntaxes/string.c)
Commit 2bac5ab553395550af33bf92082877ef6b4c5427 missed to set
an value bvp for the newly added case ((syntax & SYNTAX_DN) &&
(value_flags & SLAPI_ATTR_FLAG_NORMALIZED_CES)), which caused
the uninitialized pointer read. This patch sets bvp for all
3 cases.
(cherry picked from commit 40013a5277599aeba62cb0996bbf9860e2acbe34)

ldap/servers/plugins/syntaxes/string.c

@@ -605,6 +605,7 @@ string_values2keys( Slapi_PBlock *pb, Slapi_Value **bvals,
 				/* This dn value is case-normalized */
 				value_flags &= ~SLAPI_ATTR_FLAG_NORMALIZED_CES;
 				value_flags |= SLAPI_ATTR_FLAG_NORMALIZED_CIS;
+				bvp = slapi_value_get_berval(bvdup);
 			} else {
 				bvp = slapi_value_get_berval(*bvlp);
 			}