Use LTLIBOBJS instead of LIBOBJS for libtool library argument.
From Sylvain Beucler for crossbuilding using MinGW.

--HG--
branch : HEAD

lib/Makefile.am

diff --git a/lib/Makefile.am b/lib/Makefile.am
index 7ec890a..5baf6ba 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -3,7 +3,7 @@
 include_HEADERS = zip.h
 
 libzip_la_LDFLAGS=-version-info 1:0
-libzip_la_LIBADD=@LIBOBJS@
+libzip_la_LIBADD=@LTLIBOBJS@
 
 libzip_la_SOURCES=\
 	zip_add.c \