grep: --count over binary

grep: --count over binary

The intent of showing the message "Binary file xyz matches" for
binary files is to avoid annoying users by potentially messing up
their terminals by printing control characters.  In --count mode,
this precaution isn't necessary.

Display counts of matches if -c/--count was specified, even if -a
was not given.  GNU grep does the same.

Moving the check for ->count before the code for handling binary
file also avoids printing context lines if --count and -[ABC] were
used together, so we can remove the part of the comment that
mentions this behaviour.  Again, GNU grep does the same.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>