Change MINGW_HAS_SECURE_API checks.

MINGW_HAS_SECURE_API can be defined as 0, but this will be ignored here without this change.
Without these *_s "safe" functions, this code will also build on Windows XP.
diff --git a/glslang/Include/Common.h b/glslang/Include/Common.h
index 1e47239..e7b5e07 100644
--- a/glslang/Include/Common.h
+++ b/glslang/Include/Common.h
@@ -61,7 +61,7 @@
 }
 #endif
 
-#if (defined(_MSC_VER) && _MSC_VER < 1900 /*vs2015*/) || defined MINGW_HAS_SECURE_API
+#if (defined(_MSC_VER) && _MSC_VER < 1900 /*vs2015*/) || MINGW_HAS_SECURE_API
     #include <basetsd.h>
     #ifndef snprintf
     #define snprintf sprintf_s
@@ -213,7 +213,7 @@
 //
 // Create a TString object from an integer.
 //
-#if defined _MSC_VER || defined MINGW_HAS_SECURE_API
+#if defined _MSC_VER || MINGW_HAS_SECURE_API
 inline const TString String(const int i, const int base = 10)
 {
     char text[16];     // 32 bit ints are at most 10 digits in base 10