'callfuncs' test case: Fixes in conditionally compiled code

'callfuncs' test case: Fixes in conditionally compiled code

The C source file for the 'callfuncs' test case did not compile with
-DNO_PROTOTYPES or -DPROTOTYPES.  This patch fixes various syntax
errors under #ifdef NO_PROTOTYPES and a small typo under #ifdef
PROTOTYPES.

gdb/testsuite/ChangeLog:

	* gdb.base/callfuncs.c (t_float_many_args): Fix syntax error in
	code guarded by #ifdef NO_PROTOTYPES.
	(t_double_many_args): Likewise.
	(DEF_FUNC_MANY_ARGS_1): Likewise.
	(DEF_FUNC_VALUES_1): Likewise.
	(t_structs_ldc): Renamed from t_structs_fc in conditional code
	guarded by #ifdef PROTOTYPES.