nettle: The variable named p in the patch file was incorrectly named.

nettle: The variable named p in the patch file was incorrectly named.

The variable in question should have been called ecc->p. The patch has been updated
so that the compilation of the nettle recipe would complete successfully. The backport
originated from this commit https://git.lysator.liu.se/nettle/nettle/commit/c71d2c9d20eeebb985e3872e4550137209e3ce4d

(From OE-Core rev: 7d2476ca6d72be518189ff1441a090a896749f6a)

Signed-off-by: ngutzmann <nathangutzmann@gmail.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>