package/netsniff-ng: needs NPTL

netsniff-ng unconditionally uses pthread_spin_lock since its addition in
commit 500d287b07190c9c1a1284bc91b37d07e1a835a3 and
https://github.com/netsniff-ng/netsniff-ng/commit/1a9fbac03c684f29cff9ac44875bd9504a89f54e
resulting in the following build failure:

/home/autobuild/autobuild/instance-1/output-1/per-package/netsniff-ng/host/bin/../lib/gcc/x86_64-buildroot-linux-uclibc/10.3.0/../../../../x86_64-buildroot-linux-uclibc/bin/ld: netsniff-ng/tprintf.o: in function `tprintf_flush':
tprintf.c:(.text+0x42c): undefined reference to `pthread_spin_lock'

Fixes:
 - http://autobuild.buildroot.org/results/ceadbdea8cc35bfd7d601a6d4b18137f81f61406

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/netsniff-ng/Config.in

@@ -1,7 +1,7 @@
 config BR2_PACKAGE_NETSNIFF_NG
 	bool "netsniff-ng"
 	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_0
-	depends on BR2_TOOLCHAIN_HAS_THREADS
+	depends on BR2_TOOLCHAIN_HAS_THREADS_NPTL # pthread_spin_lock
 	depends on BR2_PACKAGE_LIBURCU_ARCH_SUPPORTS
 	select BR2_PACKAGE_LIBPCAP
 	select BR2_PACKAGE_LIBNETFILTER_CONNTRACK
@@ -28,7 +28,7 @@ comment "mausezahn needs glibc or musl toolchain"
 
 endif
 
-comment "netsniff-ng needs a toolchain w/ threads, headers >= 3.0"
+comment "netsniff-ng needs a toolchain w/ NPTL, headers >= 3.0"
 	depends on BR2_PACKAGE_LIBURCU_ARCH_SUPPORTS
-	depends on !BR2_TOOLCHAIN_HAS_THREADS || \
+	depends on !BR2_TOOLCHAIN_HAS_THREADS_NPTL || \
 		!BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_0