libmisc: Fix wrong #include

Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Iker Pedrosa <ipedrosa@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

lib/stpecpy.h

@@ -17,7 +17,7 @@
 #include <stddef.h>
 #include <string.h>
 
-#include "defines.h"
+#include "mempcpy.h"
 
 
 inline char *stpecpy(char *dst, char *end, const char *restrict src);