2重ループやめても良いか?
 while (1) {
  int c = fgetc(fp);
  if (c == EOF) {
   break;
  }
  if (c == '\n') {
   continue;
  }
  matrix[i][j] = c;
  j++;
  if (j == 10) {
   i++; j = 0;
  }
 }