compiler-rt: Fix warning if COMPILER_RT_HAS_FCNTL_LCK is 0

Fixes "warning: implicit declaration of function 'flock' is invalid in C99"
for flock().

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@369534 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed