Fix an off-by-one error which breaks this (detected by malloc flags):

the line being read in was terminated one byte too late.

usr.sbin/usbd/usbd.c

@@ -461,7 +461,7 @@ read_configuration(void)
 			exit(2);
 		}
 		strncpy(linez, line, len);
-		linez[len+1] = '\0';
+		linez[len] = '\0';
 
 		/* find the end of the current word (is field), that's the
 		 * start of the arguments