package/yasm: add CVE trailer in patch

Since Buildroot commit [1] the patches that fixes a security
vulnerability needs to reference the fixed vulnerability.

This patch adds the relevant information to the patch header.

[1] 1167d0ff3d docs/manual: mention CVE trailer

Signed-off-by: Thomas Perale <thomas.perale@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/yasm/0001-fix-null-pointer-dereference-in-yasm_expr_get_intnum.patch

@@ -10,8 +10,8 @@ For more info see:
   - https://nvd.nist.gov/vuln/detail/CVE-2021-33454
   - https://github.com/yasm/yasm/pull/244
 
+CVE: CVE-2021-33454
 Upstream: https://github.com/yasm/yasm/pull/244
-
 Signed-off-by: Titouan Christophe <titouan.christophe@mind.be>
 ---
  libyasm/expr.c | 2 +-