tools/mklibs: add missing <unistd.h> in readelf/elf.cpp

Fixes compile on my Arch Linux system, as unistd.h is needed for ::close().

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@31315 3c298f89-4303-0410-b956-a3cf2f4a3e73

tools/mklibs/patches/011-missing_unistd.patch

@@ -0,0 +1,10 @@
+--- a/src/mklibs-readelf/elf.cpp
++++ b/src/mklibs-readelf/elf.cpp
+@@ -25,6 +25,7 @@
+ #include <fcntl.h>
+ #include <sys/mman.h>
+ #include <sys/stat.h>
++#include <unistd.h>
+
+ using namespace Elf;
+