Relocated the mount point field in volume

The location of the mount point field in the volume attributes was
dependent on compiling options, thus creating an uneasy dependency
for plugins. So relocate the field to be independent on options.

include/ntfs-3g/volume.h

@@ -256,6 +256,7 @@ struct _ntfs_volume {
 	s64 free_mft_records; 	/* Same for free mft records (see above) */
 	BOOL efs_raw;		/* volume is mounted for raw access to
 				   efs-encrypted files */
+	const char *abs_mnt_point; /* Mount point */
 #ifdef XATTR_MAPPINGS
 	struct XATTRMAPPING *xattr_mapping;
 #endif /* XATTR_MAPPINGS */
@@ -274,7 +275,6 @@ struct _ntfs_volume {
 #if CACHE_LEGACY_SIZE
 	struct CACHE_HEADER *legacy_cache;
 #endif
-	const char *abs_mnt_point; /* Mount point */
 };
 
 extern const char *ntfs_home;