drop more llvm:: prefixes on SmallString<>

More cleanup after r149799.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@150380 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/IndexingContext.cpp b/tools/libclang/IndexingContext.cpp
index 47d7ff4..0493f93 100644
--- a/tools/libclang/IndexingContext.cpp
+++ b/tools/libclang/IndexingContext.cpp
@@ -994,7 +994,7 @@
     EntityInfo.name = 0; // anonymous tag/field/namespace.
 
   } else {
-    llvm::SmallString<256> StrBuf;
+    SmallString<256> StrBuf;
     {
       llvm::raw_svector_ostream OS(StrBuf);
       D->printName(OS);
@@ -1003,7 +1003,7 @@
   }
 
   {
-    llvm::SmallString<512> StrBuf;
+    SmallString<512> StrBuf;
     bool Ignore = getDeclCursorUSR(D, StrBuf);
     if (Ignore) {
       EntityInfo.USR = 0;