package/stress-ng: drop LDFLAGS_EXTRA

Drop LDFLAGS_EXTRA to fix the following build failure raised since
commit 42f25180233df459cd2bfbc5b9ebf8b95c6b60cb:

/home/buildroot/autobuild/run/instance-2/output-1/host/opt/ext-toolchain/bin/../lib/gcc/mipsel-buildroot-linux-gnu/12.3.0/../../../../mipsel-buildroot-linux-gnu/bin/ld: stress-crypt.o: in function `$L17':
stress-crypt.c:(.text+0x2dc): undefined reference to `crypt_r'

Fixes:
 - http://autobuild.buildroot.org/results/0c1d2ef59b88ebb3ae10bf8cb986280b4c1283eb

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/stress-ng/stress-ng.mk

@@ -21,7 +21,7 @@ STRESS_NG_DEPENDENCIES += keyutils
 endif
 
 ifeq ($(BR2_TOOLCHAIN_HAS_LIBATOMIC),y)
-STRESS_NG_MAKE_FLAGS += LDFLAGS_EXTRA=-latomic
+STRESS_NG_MAKE_FLAGS += LDFLAGS="$(TARGET_LDFLAGS) -latomic"
 endif
 
 define STRESS_NG_BUILD_CMDS