Clean up usbaudio, usbmouse.
 [rsc] --rw-rw-r-- M 1118886 sape sys 9843 Jan 23 09:37 sys/src/cmd/usb/audio/usbaudio.c
	/n/sourcesdump/2006/0123/plan9/sys/src/cmd/usb/audio/usbaudio.c:16,22 - 
	/n/sourcesdump/2006/0124/plan9/sys/src/cmd/usb/audio/usbaudio.c:16,22
	  
	  Channel *controlchan;
	  
	- char audstr[]		= "Enabled 0x000101\n";	/* audio.control.0 */
	+ char audstr[]		= "Enabled 0x000101";	/* audio.control.0 */
	  
	  int defaultspeed[2] = {44100, 44100};
	  
 [rsc] --rw-rw-r-- M 1118886 sape sys 3475 Jan 23 09:37 sys/src/cmd/usb/misc/usbmouse.c
	/n/sourcesdump/2006/0123/plan9/sys/src/cmd/usb/misc/usbmouse.c:1,11 - 
	/n/sourcesdump/2006/0124/plan9/sys/src/cmd/usb/misc/usbmouse.c:1,10
	  #include <u.h>
	  #include <libc.h>
	  #include <thread.h>
	- #include <stdio.h>
	  
	  int mousefd, ctlfd, mousein;
	  
	- char hbm[]		= "Enabled 0x020103\n";
	+ char hbm[]		= "Enabled 0x020103";
	  char *mouseinfile	= "/dev/mousein";
	  char *statfmt		= "/dev/usb%d/%d/status";
	  char *ctlfmt		= "/dev/usb%d/%d/ctl";
	/n/sourcesdump/2006/0123/plan9/sys/src/cmd/usb/misc/usbmouse.c:87,94 - 
	/n/sourcesdump/2006/0124/plan9/sys/src/cmd/usb/misc/usbmouse.c:86,92
	  void
	  threadmain(int argc, char *argv[])
	  {
	- 	FILE *f;
	- 	int ctlrno, i;
	+ 	int ctlrno, i, sfd;
	  	char line[256];
	  
	  	ARGBEGIN{
	/n/sourcesdump/2006/0123/plan9/sys/src/cmd/usb/misc/usbmouse.c:112,128 - 
	/n/sourcesdump/2006/0124/plan9/sys/src/cmd/usb/misc/usbmouse.c:110,126
	  	case 0:
	  		for (ctlrno = 0; ctlrno < 16; ctlrno++) {
	  			for (i = 0; i < 128; i++) {
	- 				sprint(line, statfmt, ctlrno, i);
	- 				f = fopen(line, "r");
	- 				if (f == nil)
	+ 				snprint(line, sizeof line, statfmt, ctlrno, i);
	+ 				sfd = open(line, OREAD);
	+ 				if (sfd < 0)
	  					break;
	- 				if (fgets(line, sizeof line, f) && strcmp(hbm, line) == 0) {
	+ 				if (read(sfd, line, strlen(hbm)) && strncmp(hbm, line, strlen(hbm)) == 0) {
	  					snprint(ctlfile, sizeof ctlfile, ctlfmt, ctlrno, i);
	  					snprint(msefile, sizeof msefile, msefmt, ctlrno, i);
	- 					fclose(f);
	+ 					close(sfd);
	  					goto found;
	  				}
	- 				fclose(f);
	+ 				close(sfd);
	  			}
	  		}
	  		threadexitsall("no mouse");