usp10: Silence repeated GSUB_apply_ChainContext[Subst|Pos] FIXMEs.

dlls/usp10/opentype.c

@@ -937,11 +937,15 @@ static INT GSUB_apply_ChainContextSubst(const OT_LookupList* lookup, const OT_Lo
         ccsf1 = (const GSUB_ChainContextSubstFormat1*)((const BYTE*)look+offset);
         if (GET_BE_WORD(ccsf1->SubstFormat) == 1)
         {
+            static int once;
+            if (!once++)
                 FIXME("  TODO: subtype 1 (Simple context glyph substitution)\n");
             continue;
         }
         else if (GET_BE_WORD(ccsf1->SubstFormat) == 2)
         {
+            static int once;
+            if (!once++)
                 FIXME("  TODO: subtype 2 (Class-based Chaining Context Glyph Substitution)\n");
             continue;
         }
@@ -1648,11 +1652,15 @@ static INT GPOS_apply_ChainContextPos(ScriptCache *psc, LPOUTLINETEXTMETRICW lpo
 
         if (GET_BE_WORD(ccpf3->PosFormat) == 1)
         {
+            static int once;
+            if (!once++)
                 FIXME("  TODO: subtype 1 (Simple Chaining Context Glyph Positioning)\n");
             continue;
         }
         else if (GET_BE_WORD(ccpf3->PosFormat) == 2)
         {
+            static int once;
+            if (!once++)
                 FIXME("  TODO: subtype 2 (Class-based Chaining Context Glyph Positioning)\n");
             continue;
         }