Fix compiler warning

ibscdl.c:30: warning: no previous prototype for 'sc_dlopen'
libscdl.c:35: warning: no previous prototype for 'sc_dlsym'
libscdl.c:40: warning: no previous prototype for 'sc_dlerror'
libscdl.c:45: warning: no previous prototype for 'sc_dlclose'


git-svn-id: https://www.opensc-project.org/svnp/opensc/trunk@5249 c6295689-39f2-0310-b995-f0e70906c6a9

src/common/libscdl.c

@@ -20,6 +20,8 @@
 
 #include "config.h"
 
+#include "libscdl.h"
+
 #ifdef HAVE_LTDL_H
 #include <ltdl.h>
 /* libltdl is present, pass all calls to it */