xhci: Rate-limit XHCI_TRUST_TX_LENGTH quirk warning.

When we encounter an xHCI host that needs the XHCI_TRUST_TX_LENGTH
quirk, the xHCI driver ends up spewing messages about the quirk into
dmesg every time a short packet occurs.  Change the xHCI driver to
rate-limit such warnings.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: Matthew Hall <mhall@mhcomputing.net>
Reported-by: Gary E. Miller <gem@rellim.com>

drivers/usb/host/xhci-ring.c

@@ -2073,8 +2073,8 @@ static int handle_tx_event(struct xhci_hcd *xhci,
 		if (xhci->quirks & XHCI_TRUST_TX_LENGTH)
 			trb_comp_code = COMP_SHORT_TX;
 		else
-			xhci_warn(xhci, "WARN Successful completion on short TX: "
-					"needs XHCI_TRUST_TX_LENGTH quirk?\n");
+			xhci_warn_ratelimited(xhci,
+					"WARN Successful completion on short TX: needs XHCI_TRUST_TX_LENGTH quirk?\n");
 	case COMP_SHORT_TX:
 		break;
 	case COMP_STOP:

drivers/usb/host/xhci.h

@@ -1537,6 +1537,8 @@ static inline struct usb_hcd *xhci_to_hcd(struct xhci_hcd *xhci)
 	dev_err(xhci_to_hcd(xhci)->self.controller , fmt , ## args)
 #define xhci_warn(xhci, fmt, args...) \
 	dev_warn(xhci_to_hcd(xhci)->self.controller , fmt , ## args)
+#define xhci_warn_ratelimited(xhci, fmt, args...) \
+	dev_warn_ratelimited(xhci_to_hcd(xhci)->self.controller , fmt , ## args)
 
 /* TODO: copied from ehci.h - can be refactored? */
 /* xHCI spec says all registers are little endian */