Add static qualifier.

This is neccessary to make sure that we have a version if the function is not actually inlined.

src/status_to_string.h

@@ -4,7 +4,7 @@
 extern "C" {
 #endif
 
-inline const char *pEp_status_to_string(PEP_STATUS status) {
+static inline const char *pEp_status_to_string(PEP_STATUS status) {
     switch (status) {
     case PEP_STATUS_OK: return "PEP_STATUS_OK";