agent: Rename the internal function for ECC KEM.
* agent/pkdecrypt.c (ecc_kem_decap): Rename from ecc_pgp_kem_decap, since it also handles the CMS case. (composite_pgp_kem_decrypt, ecc_kem_decrypt): Follow the change.
- GnuPG-bug-id: T7811
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>