Fix build failure on Windows due to undefined cflags identifier

Reviewed-by: NTim Hudson <tjh@openssl.org>

crypto/cversion.c

@@ -77,7 +77,7 @@ const char *SSLeay_version(int t)
 	if (t == SSLEAY_CFLAGS)
 		{
 #ifdef CFLAGS
-		return(cflags);
+		return(CFLAGS);
 #else
 		return("compiler: information not available");
 #endif

util/mkbuildinf.pl

@@ -7,7 +7,7 @@ $date = localtime();
 print <<"END_OUTPUT";
 #ifndef MK1MF_BUILD
     /* auto-generated by util/mkbuildinf.pl for crypto/cversion.c */
-    #define CFLAGS
+    #define CFLAGS cflags
     /*
      * Generate CFLAGS as an array of individual characters. This is a
      * workaround for the situation where CFLAGS gets too long for a C90 string