FIXED: CALL failing post indirect_value_id removal

Change details:
As indirect_value_id is no longer used, "function pointer" as a source to CALL instruction is not a valid case.
A LOAD instruction is used in the "function pointer" case.
This reverts a small part of commit a1dda333d569a7ae2af71528ce90eb5cc90ca7e9.

Signed-off-by: Arun Prakash Jana <engineerarun@gmail.com>
Signed-off-by: James Courtier-Dutton <James@superbug.co.uk>