mtd: nand: remove unnecessary 'extern' from function declarations

'extern' is not necessary for function declarations. To prevent
people from adding the keyword to new declarations remove the
existing ones.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
[Linux commit: 79022591839f110f465cac0223e117b91d47d5db]
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
1 file changed