[CMake] Removing extra underscore.

Fixing a typo.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@252534 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/cmake/Modules/CompilerRTDarwinUtils.cmake b/cmake/Modules/CompilerRTDarwinUtils.cmake
index 27c6479..2e96820 100644
--- a/cmake/Modules/CompilerRTDarwinUtils.cmake
+++ b/cmake/Modules/CompilerRTDarwinUtils.cmake
@@ -361,7 +361,7 @@
   set(SOFT_FLOAT_FLAG -mfloat-abi=soft)
   set(HARD_FLOAT_FLAG -mfloat-abi=hard)
 
-  set(PIC_FLAG_ -fPIC)
+  set(PIC_FLAG -fPIC)
   set(STATIC_FLAG -static)
 
   darwin_test_archs(ios