boot: fix ramdisk paths lost to FAT name uppercasing; widen driver-name buffers

The EFI loader now ENUMERATES /system rather than opening files by name,
so the on-disk name must be exact, not merely case-insensitively
findable. make-fat-image.py stored 8.3-fitting lowercase names as bare
uppercase short entries ('init' -> INIT), garbling the ramdisk paths;
now any name whose case the 8.3 entry cannot reproduce gets a long-name
chain carrying the exact name.

device-manager's driver table stored names in 24 bytes — silently
truncating '/system/drivers/usb-xhci-bus' and failing the spawn; widen
to 64 (= abi.maximum_process_name). The usb-report harness regex learns
that restart lines name drivers by path.

test/qemu_test.py

@@ -447,7 +447,7 @@ CASES = [
                r"device-manager: child added[\s\S]*"
                r"device-manager: test mode: killing the reporter[\s\S]*"
                r"device-manager: child removed[\s\S]*"
-               r"device-manager: restarting usb-xhci-bus[\s\S]*"
+               r"device-manager: restarting \S*usb-xhci-bus[\s\S]*"
                r"device-manager: child added",
      "fail":   r"DANOS-TEST-RESULT: FAIL"},
     # USB HID end to end: boot the full tree, enumerate the xHCI, and let the