Bug 1663119 - Remove mingw workaround for _ftelli64/_fseeki64 r=tjr

Differential Revision: https://phabricator.services.mozilla.com/D94658

modules/libmar/src/mar_private.h

@@ -57,15 +57,8 @@ static_assert(sizeof(BLOCKSIZE) < (SIGNATURE_BLOCK_OFFSET + sizeof(uint32_t)),
 /* Include stdio.h before redefining ftello and fseeko to avoid clobbering
  * the ftello() and fseeko() function declarations in MinGW's stdio.h. */
 #  include <stdio.h>
-#  ifdef __MINGW32__
-/* Avoid MinGW's _ftelli64() and _fseeki64() implementations because they
- * are unreliable. */
-#    define ftello ftello64
-#    define fseeko fseeko64
-#  else
-#    define ftello _ftelli64
-#    define fseeko _fseeki64
-#  endif
+#  define ftello _ftelli64
+#  define fseeko _fseeki64
 #else
 #  define _FILE_OFFSET_BITS 64
 #  include <netinet/in.h>