gallivm: Fix build since llvm-3.7.0svn r234495

Revert 50e9fa2ed6 as LLVM reverted their
change.

Signed-off-by: Nick Sarnie <commendsarnex@gmail.com>
Reviewed-by: Jan Vesely <jan.vesely@rutgers.edu>

src/gallium/auxiliary/gallivm/lp_bld_debug.cpp

@@ -97,11 +97,7 @@ private:
    uint64_t pos;
 
 public:
-#if HAVE_LLVM >= 0x0307
-   raw_debug_ostream() : raw_ostream(SK_FD), pos(0) { }
-#else
    raw_debug_ostream() : pos(0) { }
-#endif
 
    void write_impl(const char *Ptr, size_t Size);