[source] zlib: use default Build/Configure rule

[LEDE Commits]

jow pushed a commit to source.git, branch lede-17.01:
https://git.lede-project.org/610e2afdcc2a0d7ba56dccc5c941437f89d58727

commit 610e2afdcc2a0d7ba56dccc5c941437f89d58727
Author: Stijn Tintel <stijn at linux-ipv6.be>
AuthorDate: Sat Mar 11 09:32:19 2017 +0100

    zlib: use default Build/Configure rule
    
    Signed-off-by: Stijn Tintel <stijn at linux-ipv6.be>
    (cherry picked from commit 462ca4e059dbead678163da26fb4e14748f3021e)
---
 package/libs/zlib/Makefile | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/package/libs/zlib/Makefile b/package/libs/zlib/Makefile
index 902381b..7e3bd83 100644
--- a/package/libs/zlib/Makefile
+++ b/package/libs/zlib/Makefile
@@ -45,17 +45,15 @@ define Package/zlib-dev/description
  This package includes the development support files.
 endef
 
-define Build/Configure
-	(cd $(PKG_BUILD_DIR); \
-		$(TARGET_CONFIGURE_OPTS) \
-		LDSHARED="$(TARGET_CC) -shared -Wl,-soname,libz.so.1" \
-		CFLAGS="$(TARGET_CFLAGS) $(FPIC)" \
-		./configure \
-			--prefix=/usr \
-			--shared \
-			--uname=Linux \
-	);
-endef
+CONFIGURE_VARS := \
+	$(TARGET_CONFIGURE_OPTS) \
+	LDSHARED="$(TARGET_CC) -shared -Wl,-soname,libz.so.1" \
+	CFLAGS="$(TARGET_CFLAGS) $(FPIC)" \
+
+CONFIGURE_ARGS := \
+	--prefix=/usr \
+	--shared \
+	--uname=Linux \
 
 define Build/Compile
 	+$(MAKE) $(PKG_JOBS) -C $(PKG_BUILD_DIR) \