USB: musb: host side diagnostics tweaks

Random host-side MUSB updates, mostly relating to better diagnostics:

 + Improve diagnostics on host side:
    - tx flush fifo:
       * Avoid hundreds of duplicate TX FIFONOTEMPTY messages
       * make "Can't flush TX fifo" a warning, and say which endpoint
    - giveback:
       * use correct status code
       * show completion function name not just URB pointer
    - Fix annoying "1 bytes" (should be "1 byte")

 + Be more consistent about failing init of unusable fifo_mode

It's not clear why that "can't flush TX fifo" message appears, though
it might relate to disconnection; I see it not infrequently

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index de7f8be..8b14437 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -1212,7 +1212,7 @@
 		if (epn >= musb->config->num_eps) {
 			pr_debug("%s: invalid ep %d\n",
 					musb_driver_name, epn);
-			continue;
+			return -EINVAL;
 		}
 		offset = fifo_setup(musb, hw_ep + epn, cfg++, offset);
 		if (offset < 0) {
@@ -1813,7 +1813,6 @@
 	for (epnum = 0, ep = musb->endpoints;
 			epnum < musb->config->num_eps;
 			epnum++, ep++) {
-
 		ep->musb = musb;
 		ep->epnum = epnum;
 	}