[LTP] Use of -pthread

[Steve East]

I see a few tests adding -pthread to CFLAGS in the Makefile:

sge@oststbldvm09 ltp $ find . -name Makefile|xargs grep -- -pthread
./lib/newlib_tests/Makefile:test08: CFLAGS+=-pthread
./lib/newlib_tests/Makefile:test09: CFLAGS+=-pthread
./lib/tests/Makefile:tst_cleanup_once: CFLAGS += -pthread
./testcases/kernel/mem/hugetlb/hugemmap/Makefile:hugemmap06: CFLAGS+=-pthread
./testcases/kernel/security/dirtyc0w/Makefile:dirtyc0w_child: CFLAGS+=-pthread
./testcases/kernel/syscalls/futex/Makefile:futex_wait03: CFLAGS+=-pthread
./testcases/kernel/syscalls/futex/Makefile:futex_wake02: CFLAGS+=-pthread
./testcases/kernel/syscalls/futex/Makefile:futex_wake04: CFLAGS+=-pthread
./testcases/kernel/syscalls/sched_getattr/Makefile:CFLAGS                       += -pthread
./testcases/kernel/syscalls/sched_setattr/Makefile:CFLAGS                       += -pthread
./testcases/kernel/syscalls/signal/Makefile:signal06: CFLAGS+=-pthread


Other tests (50+) use:

LDLIBS += -lpthread

Instead. 

Any reason for the difference?

Steve.