Fix compile error in certain cases

I'm not sure why it doesn't happen everywhere, but we need <sys/stat.h> for
umask and mkdir in this file. I hit this today:

cc1: warnings being treated as errors
util.c: In function ‘makepath’:
util.c:128:2: error: implicit declaration of function ‘umask’
util.c:141:5: error: implicit declaration of function ‘mkdir’
make[2]: *** [util.o] Error 1

Signed-off-by: Dan McGee <dan@archlinux.org>

src/pacman/util.c

@@ -22,6 +22,7 @@
 
 #include <sys/types.h>
 #include <sys/ioctl.h>
+#include <sys/stat.h>
 #include <sys/time.h>
 
 #include <stdio.h>