libcasper: explicit cast in cap_fileargs header

The implicit cast is incompatible with standard compiler options in a
C++ project, making the library difficult to use.

Signed-off-by: Quentin Thébault <quentin.thebault@defenso.fr>
Sponsored by: Defenso
MFC after: 3 days
Discussed with: kevans
Reviewed by: emaste, vexeduxr
Pull request: https://github.com/freebsd/freebsd-src/pull/1857

lib/libcasper/services/cap_fileargs/cap_fileargs.h

@@ -75,7 +75,7 @@ fileargs_init(int argc __unused, char *argv[] __unused, int flags, mode_t mode,
     cap_rights_t *rightsp __unused, int operations __unused) {
 	fileargs_t *fa;
 
-	fa = malloc(sizeof(*fa));
+	fa = (fileargs_t *)malloc(sizeof(*fa));
 	if (fa != NULL) {
 		fa->fa_flags = flags;
 		fa->fa_mode = mode;