fontsrv: use 64 chars per subfont instead of 256

Makes loading faster, and makes larger sizes not too wide.

Change-Id: I076c83fdb9577c1e596de45558f38ea93e3a2a31
Reviewed-on: https://plan9port-review.googlesource.com/1360
Reviewed-by: Russ Cox <rsc@swtch.com>

src/libdraw/openfont.c

@@ -61,7 +61,7 @@ openfont1(Display *d, char *name)
 		n = _drawflength(fd);
 	if(fd < 0 && strncmp(fname, "/mnt/font/", 10) == 0) {
 		fd = _fontpipe(fname+10);
-		n = 8192;
+		n = 128*1024;
 	}
 	if(fd < 0)
 		return 0;