can: usb: peak: rename peak_usb dump_mem function

Rename generic-sounding function dump_mem() to pcan_dump_mem()
so that it does not conflict with the dump_mem() function in
arch/sh/include/asm/kdebug.h.

drivers/net/can/usb/peak_usb/pcan_usb_core.c: error: conflicting types for 'dump_mem':  => 56:6
drivers/net/can/usb/peak_usb/pcan_usb_core.h: error: conflicting types for 'dump_mem':  => 134:6

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Stephane Grosjean <s.grosjean@peak-system.com>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
[mkl: convert all users of dump_mem(), too]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>