[C] Simplified code

Author: seleznevae

appveyor.yml

@@ -15,7 +15,7 @@ before_build:
   - dir
   - cd build
   - dir
-  - cmake -G "Visual Studio 15 2017 Win64" .. -DCERAII_DO_BEFORE_EXIT=ON 
+  - cmake -G "Visual Studio 15 2017 Win64" ..
 
 build:
   project: $(APPVEYOR_BUILD_FOLDER)\build\$(APPVEYOR_PROJECT_NAME).sln

src/ceraii.h

@@ -43,9 +43,7 @@ SOFTWARE.
 #endif
 
 #ifdef CERAII_MICROSOFT_COMPILER
-#ifndef CERAII_ACTIONS_BEFORE_RETURN_EXPRESSION
-#error ceraii: Doing actions after evaluating return expression is available onlu in gcc and clang
-#endif
+#define CERAII_ACTIONS_BEFORE_RETURN_EXPRESSION
 #endif
 
 #ifdef __cplusplus