Fix uninitialized varible in zfs_do_userspace()

When compiling under Debian Lenny with gcc version 4.3.2
(Debian 4.3.2-1.1) the following warning occurs.  To quiet
the warning initialize 'error' to zero.  Newer versions of
gcc correctly determine that this uninitialized varible is
impossible because ZFS_NUM_USERQUOTA_PROPS is known to be
greater than zero.

  cmd/zfs/zfs_main.c:2377: warning: "error" may be
  used uninitialized in this function

Signed-off-by: Brian Behlendorf <[email protected]>

cmd/zfs/zfs_main.c

@@ -2374,7 +2374,7 @@ zfs_do_userspace(int argc, char **argv)
 	boolean_t prtnum = B_FALSE;
 	boolean_t parseable = B_FALSE;
 	boolean_t sid2posix = B_FALSE;
-	int error;
+	int error = 0;
 	int c;
 	zfs_sort_column_t *default_sortcol = NULL;
 	zfs_sort_column_t *sortcol = NULL;