efreet: fix undeclared function

libgen is needed on OSX because it contains the prototype
of basename() which is required in the compiling unit.
The result of basename() was therefore implicitely converted into
an integer, which could leed to subtile issues.

@fix

src/bin/efreet/efreet_desktop_cache_create.c

@@ -12,9 +12,10 @@
 
 #ifdef _WIN32
 # include <winsock2.h>
-# include <libgen.h>
 #endif
 
+#include <libgen.h>
+
 #include <Eina.h>
 #include <Eet.h>
 #include <Ecore.h>