Fix #2007: Fix a couple relative header paths in header files.

SPIRV/GlslangToSpv.h

diff --git a/SPIRV/GlslangToSpv.h b/SPIRV/GlslangToSpv.h
index 86e1c23..3907be4 100755
--- a/SPIRV/GlslangToSpv.h
+++ b/SPIRV/GlslangToSpv.h
@@ -40,7 +40,7 @@
 #endif
 
 #include "SpvTools.h"
-#include "../glslang/Include/intermediate.h"
+#include "glslang/Include/intermediate.h"
 
 #include <string>
 #include <vector>

SPIRV/SpvTools.h

diff --git a/SPIRV/SpvTools.h b/SPIRV/SpvTools.h
index 7422d01..59c914d 100644
--- a/SPIRV/SpvTools.h
+++ b/SPIRV/SpvTools.h
@@ -46,7 +46,7 @@
 #include <ostream>
 #endif
 
-#include "../glslang/MachineIndependent/localintermediate.h"
+#include "glslang/MachineIndependent/localintermediate.h"
 #include "Logger.h"
 
 namespace glslang {