[binutils-gdb] Code cleanup: dwarf2read.c: Eliminate ::file_write

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT a81e6d4d261b7471428408f4ebba1b8113c16ccf ***

Author: Pedro Alves <palves@redhat.com>
Branch: master
Commit: a81e6d4d261b7471428408f4ebba1b8113c16ccf

Code cleanup: dwarf2read.c: Eliminate ::file_write

There's no real need for all this indirection.

gdb/ChangeLog:
2017-06-12  Pedro Alves  <palves@redhat.com>

	* dwarf2read.c (file_write(FILE *, const void *, size_t)): Delete.
	(file_write (FILE *, const std::vector<Elem>&)): Delete.
	(data_buf::file_write): Call ::fwrite directly.