usb/early: Remove trace_printk() callers in xhci-dbc

Trace_printk() was used to log debug messages in xhci-dbc.c where
printk() isn't feasible. As there should not be a single caller to
trace_printk() in normal kernels, replace them with empty functions.

Cc: Vlastimil Babka <vbabka.lkml@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/early/xhci-dbc.c

@@ -32,7 +32,6 @@
 static struct xdbc_state xdbc;
 static bool early_console_keep;
 
-#define XDBC_TRACE
 #ifdef XDBC_TRACE
 #define	xdbc_trace	trace_printk
 #else