Fix bad headers when used from C++ (#43)

* Fix bad headers when used from C++

Tested compilation with both gcc (using the Makefile) and clang
(which is needed to compile the code into an enclave usable
with the Open Enclave SDK).

Signed-off-by: Dave Thaler <dthaler@microsoft.com>

* Same fix for qcbor_decode.h

Signed-off-by: Dave Thaler <dthaler@microsoft.com>
diff --git a/inc/qcbor/qcbor_decode.h b/inc/qcbor/qcbor_decode.h
index b028e4c..710ab81 100644
--- a/inc/qcbor/qcbor_decode.h
+++ b/inc/qcbor/qcbor_decode.h
@@ -42,7 +42,7 @@
 
 #ifdef __cplusplus
 extern "C" {
-#ifdef 0
+#if 0
 } // Keep editor indention formatting happy
 #endif
 #endif
@@ -936,5 +936,8 @@
    return 0;
 }
 
+#ifdef __cplusplus
+}
+#endif 
 
 #endif /* qcbor_decode_h */
diff --git a/inc/qcbor/qcbor_encode.h b/inc/qcbor/qcbor_encode.h
index 83c8bbf..31fda52 100644
--- a/inc/qcbor/qcbor_encode.h
+++ b/inc/qcbor/qcbor_encode.h
@@ -42,7 +42,7 @@
 
 #ifdef __cplusplus
 extern "C" {
-#ifdef 0
+#if 0
 } // Keep editor indention formatting happy
 #endif
 #endif
diff --git a/inc/qcbor/qcbor_private.h b/inc/qcbor/qcbor_private.h
index 6bc3f70..a7cb440 100644
--- a/inc/qcbor/qcbor_private.h
+++ b/inc/qcbor/qcbor_private.h
@@ -41,7 +41,7 @@
 
 #ifdef __cplusplus
 extern "C" {
-#ifdef 0
+#if 0
 } // Keep editor indention formatting happy
 #endif
 #endif
@@ -181,5 +181,8 @@
 #define CBOR_MAJOR_NONE_TYPE_ARRAY_INDEFINITE_LEN 12
 #define CBOR_MAJOR_NONE_TYPE_MAP_INDEFINITE_LEN 13
 
+#ifdef __cplusplus
+}
+#endif
 
 #endif /* qcbor_private_h */