Do not add -lresolv on non-Linux systems

On FreeBSD getaddrinfo and friends are part of libc.
Other OS-es will also have own dependencies

Signed-off-by: Alex Samorukov <samm@os2.kiev.ua>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/Makefile.flags b/Makefile.flags
index 6ff4d72..5673bc4 100644
--- a/Makefile.flags
+++ b/Makefile.flags
@@ -181,8 +181,10 @@
 endif
 
 ifeq ($(CONFIG_FEATURE_NSLOOKUP_BIG),y)
+ifeq ($(CONFIG_UNAME_OSNAME),Linux)
 LDLIBS += resolv
 endif
+endif
 
 ifeq ($(CONFIG_EFENCE),y)
 LDLIBS += efence