fixed indentation for printing Fortran types with pointers

Printing the prefix "PTR TO -> (" resp. "REF TO ->(" ignored the
active indentation level. This caused inconsistent appearance of
user-defined Fortran types containing pointers. Fixed by using
"fprintfi_filtered" with the current indentation level for outputting
the prefix string.

Changelog:
	11/16/2012 Frank Penczek <frank.penczek@intel.com>

	* f-typeprint.c(f_type_print_base): use fprintfi_filtered to maintain
	  proper indentation when printing pointers/refs

Signed-off-by: Frank Penczek <frank.penczek@intel.com>
Change-Id: I5b9ef748720a5fd38e3f34027b27d8cf71034227