Fixes:
agent.c: In function '_DtCm_init_agent':
agent.c:160: warning: passing argument 5 of 'registerrpc' from incompatible pointer type
agent.c:160: warning: passing argument 6 of 'registerrpc' from incompatible pointer type
agent.c:167: warning: passing argument 5 of 'registerrpc' from incompatible pointer type
agent.c:167: warning: passing argument 6 of 'registerrpc' from incompatible pointer type
This is a non-POSIX/ISO-C header. It is ok to include this on Linux, but it
is obsolete on BSD; FreeBSD even throws an error if you include it with
__STDC__ defined. Every system should nowadays have malloc() defined in
stdlib.h.
Diff is largely mechanical, replacing malloc.h with stdlib.h where it is not
yet included anyway.