serial: mvebu-uart: drop incorrect memset

serial: mvebu-uart: drop incorrect memset

gcc points out that the length passed into memset here is wrong:

drivers/tty/serial/mvebu-uart.c: In function 'mvebu_uart_probe':
arch/x86/include/asm/string_32.h:324:29: error: 'memset' used with length equal to number of elements without multiplication by element size [-Werror=memset-elt-size]

Moreover, the structure was allocated with kzalloc a few lines earlier,
so that memset is also unnecessary. Let's drop it to shut up the
compiler warning.

Fixes: 95f787685a22 ("serial: mvebu-uart: dissociate RX and TX interrupts")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>