vsftpd: fix musl compatibility

Make vsftpd to compile with musl, while preserving uclibc compatibility.

When using musl:
* disable UTMPX functionality
* disable -lnsl option in upstream Makefile

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>

net/vsftpd/Makefile

 #
-# Copyright (C) 2006-2014 OpenWrt.org
+# Copyright (C) 2006-2015 OpenWrt.org
 #
 # This is free software, licensed under the GNU General Public License v2.
 # See /LICENSE for more information.
 
 PKG_NAME:=vsftpd
 PKG_VERSION:=3.0.2
-PKG_RELEASE:=4
+PKG_RELEASE:=5
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://security.appspot.com/downloads/
 
 Package/vsftpd-tls/conffiles=$(Package/vsftpd/conffiles)
 
+ifneq ($(CONFIG_USE_MUSL),)
+  NLSSTRING:=-lcrypt
+else
+  NLSSTRING:=-lcrypt -lnsl
+endif
+
 ifeq ($(BUILD_VARIANT),notls)
  define Build/Compile
+	$(SED) 's/-lcrypt -lnsl/$(NLSSTRING)/' $(PKG_BUILD_DIR)/Makefile
 	$(MAKE) -C $(PKG_BUILD_DIR) \
 		CC="$(TARGET_CC)" \
 		CFLAGS="$(TARGET_CFLAGS)" \
  define Build/Compile
 	$(SED) 's/#undef VSF_BUILD_SSL/#define VSF_BUILD_SSL/' $(PKG_BUILD_DIR)/builddefs.h
 	$(SED) 's/-lcrypt -lnsl/-lcrypt -lnsl -lssl -lcrypto/' $(PKG_BUILD_DIR)/Makefile
+	$(SED) 's/-lcrypt -lnsl/$(NLSSTRING)/' $(PKG_BUILD_DIR)/Makefile
 	$(MAKE) -C $(PKG_BUILD_DIR) \
 		CC="$(TARGET_CC)" \
 		CFLAGS="$(TARGET_CFLAGS)" \

net/vsftpd/patches/006-musl-compatibility.patch

+--- a/sysdeputil.c
++++ b/sysdeputil.c
+@@ -58,7 +58,9 @@
+ #define VSF_SYSDEP_HAVE_SHADOW
+ #define VSF_SYSDEP_HAVE_USERSHELL
+ #define VSF_SYSDEP_HAVE_LIBCAP
+-#define VSF_SYSDEP_HAVE_UTMPX
++#if defined(__GLIBC__) || defined(__UCLIBC__)
++  #define VSF_SYSDEP_HAVE_UTMPX
++#endif
+ 
+ #define __USE_GNU
+ #include <utmpx.h>