USB: serial: Remove unnecessary \n's from dbg uses

#define dbg adds the newline, messages shouldn't.
Converted dbg("%s", "some string") to dbg("some string")

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index 0b1c473..5288203 100644
--- a/drivers/usb/serial/generic.c
+++ b/drivers/usb/serial/generic.c
@@ -194,7 +194,7 @@
 		if (port->urbs_in_flight >
 		    port->serial->type->max_in_flight_urbs) {
 			spin_unlock_irqrestore(&port->lock, flags);
-			dbg("%s - write limit hit\n", __func__);
+			dbg("%s - write limit hit", __func__);
 			return bwrite;
 		}
 		port->tx_bytes_flight += towrite;