package/zip: fix musl static build

package/zip: fix musl static build

Fix the following static build failure on musl which is raised because
the "Check for directory libraries" in configure wrongly adds -DNO_DIR
when no directory library is needed:

/tmp/instance-0/output-1/host/bin/arm-buildroot-linux-musleabihf-gcc -c -D_FILE_OFFSET_BITS=64 -O2 -g0 -static -I. -DUNIX -DUIDGID_NOT_16BIT -DBZIP2_SUPPORT -DLARGE_FILE_SUPPORT -DUNICODE_SUPPORT -DNO_MKTIME -DNO_DIR -DHAVE_DIRENT_H -DHAVE_TERMIOS_H unix/unix.c
unix/unix.c:70:14: error: conflicting types for 'DIR'
   70 | typedef FILE DIR;
      |              ^~~

Fixes:
 - http://autobuild.buildroot.org/results/83a6e0c8c4ad026cb0261246e3b1a80d754454bd

Patch not sent upstream since upstream is dead.

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>