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: 7f4d3b90840a14d660a56d23e1fe79f4fb633d59)

Signed-off-by: ngutzmann <nathangutzmann@gmail.com>
Signed-off-by: Joshua Lock <joshua.g.lock@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-support/nettle/nettle-2.7.1/CVE-2015-8803_8805.patch

@@ -40,7 +40,7 @@ Index: nettle-2.7.1/ecc-256.c
        u1 -= cy;
 -      u1 += cnd_add_n (t, rp + n - 4, ecc->p, 3);
 +
-+      cy = cnd_add_n (t, rp + n - 4, p->m, 2);
++      cy = cnd_add_n (t, rp + n - 4, ecc->p, 2);
 +      u0 += cy;
 +      u1 += (u0 < cy);
        u1 -= (-t) & 0xffffffff;