bfd targmatch.h makefile rule

bfd targmatch.h makefile rule

I hit this just now with a make -j build after touching config.bfd.
mv: cannot stat 'targmatch.new': No such file or directory
make[2]: *** [Makefile:2336: targmatch.h] Error 1
make[2]: *** Waiting for unfinished jobs....

Fix that by not removing the target of the rule, a practice that seems
likely to cause parallel running of the rule recipe.  The bug goes
back to 1997, the initial c0734708814c commit.

	* Makefile.am (targmatch.h): rm the temp file, not targmatch.h.
	* Makefile.in: Regenerate.