Add missing extern "C" to umf.h

Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com>

Author: ldorau

include/umf.h

@@ -15,6 +15,10 @@
 #include <umf/mempolicy.h>
 #include <umf/memspace.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 ///
 /// @brief  Increment the usage reference counter and initialize the global state of libumf
 ///         if the usage reference counter was equal to 0.
@@ -28,4 +32,8 @@ int umfInit(void);
 ///        It must be called just before dlclose() and it is not required in other scenarios.
 void umfTearDown(void);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* UMF_UNIFIED_MEMORY_FRAMEWORK_H */