Add explicit c10:: namespace to converter (pytorch#13593)

Summary:
Pull Request resolved: pytorch#13593

Should fix up master

Reviewed By: orionr

Differential Revision: D12929779

fbshipit-source-id: 23119f5bf1d9f1e37e8ed01bfa2cc40647725390

aten/src/ATen/core/Scalar.h

@@ -30,11 +30,10 @@ class CAFFE2_API Scalar {
 
 #undef DEFINE_IMPLICIT_CTOR
 
-#define DEFINE_IMPLICIT_COMPLEX_CTOR(type,name,member) \
-  Scalar(type vv) \
-  : tag(Tag::HAS_##member) { \
-    v . member[0] = convert<double>(vv.real()); \
-    v . member[1] = convert<double>(vv.imag()); \
+#define DEFINE_IMPLICIT_COMPLEX_CTOR(type, name, member) \
+  Scalar(type vv) : tag(Tag::HAS_##member) {             \
+    v.member[0] = c10::convert<double>(vv.real());       \
+    v.member[1] = c10::convert<double>(vv.imag());       \
   }
 
   DEFINE_IMPLICIT_COMPLEX_CTOR(at::ComplexHalf,ComplexHalf,z)