[lldb-server] No need to add pthread twice.

Summary:
Following on from r247991:
pthread is in LLDB_SYSTEM_LIBS so there's no need to explicitly add it to the link.

Reviewers: labath

Subscribers: lldb-commits, labath, krytarowski

Differential Revision: http://reviews.llvm.org/D12964

llvm-svn: 248177

lldb/tools/lldb-server/CMakeLists.txt

@@ -27,9 +27,6 @@ if (BUILD_SHARED_LIBS )
     )
 
   target_link_libraries(lldb-server liblldb)
-  if (HAVE_LIBPTHREAD)
-    target_link_libraries(lldb-server pthread)
-  endif ()
   target_link_libraries(lldb-server ${LLDB_SYSTEM_LIBS})
 else()
   add_lldb_executable(lldb-server