win32: replace usage of _MSV_VER with _MSC_VER

src/tsort.c

@@ -18,7 +18,7 @@
 
 #if defined(__GNUC__)
 #	define CLZ(x) __builtin_clz(x)
-#elif defined(_MSV_VER)
+#elif defined(_MSC_VER)
 #	define CLZ(x) _CountLeadingZeros(x)
 #else
 int CLZ(int32_t x)

src/util.c

@@ -5,7 +5,7 @@
 #include <ctype.h>
 #include "posix.h"
 
-#ifdef _MSV_VER
+#ifdef _MSC_VER
 # include <Shlwapi.h>
 #endif
 

src/win32/posix.c

@@ -211,7 +211,7 @@ char *p_realpath(const char *orig_path, char *buffer)
 
 int p_vsnprintf(char *buffer, size_t count, const char *format, va_list argptr)
 {
-#ifdef _MSV_VER
+#ifdef _MSC_VER
 	int len = _vsnprintf(buffer, count, format, argptr);
 	return (len < 0) ? _vscprintf(format, argptr) : len;
 #else /* MinGW */