staging: android: ram_console use kmemdup instead of kmalloc

Replace kmalloc + memcpy will kmemdup in ram_console_late_init

Signed-off-by: Greg Dietsche <Gregory.Dietsche@cuw.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change-Id: I301a21053460b81bae438fa2b4b14eb068848668