kboot: Use (void) instead of () for functiosn with no args

`int foo();` means 'a function that takes any number of arguments.`
not `a function that takes no arguemnts`, that's spelled `int foo(void);`
Adopt the latter.

Sponsored by:		Netflix

stand/kboot/hostcons.c

@@ -34,8 +34,8 @@ __FBSDID("$FreeBSD$");
 static void hostcons_probe(struct console *cp);
 static int hostcons_init(int arg);
 static void hostcons_putchar(int c);
-static int hostcons_getchar();
-static int hostcons_poll();
+static int hostcons_getchar(void);
+static int hostcons_poll(void);
 
 struct console hostconsole = {
 	"host",
@@ -79,7 +79,7 @@ hostcons_putchar(int c)
 }
 
 static int
-hostcons_getchar()
+hostcons_getchar(void)
 {
 	uint8_t ch;
 	int rv;
@@ -91,7 +91,7 @@ hostcons_getchar()
 }
 
 static int
-hostcons_poll()
+hostcons_poll(void)
 {
 	struct host_timeval tv = {0,0};
 	long fds = 1 << 0;

stand/kboot/main.c

@@ -125,7 +125,7 @@ kboot_rsdp_from_efi(void)
 }
 
 static void
-find_acpi()
+find_acpi(void)
 {
 	rsdp = kboot_rsdp_from_efi();
 #if 0	/* maybe for amd64 */
@@ -135,13 +135,13 @@ find_acpi()
 }
 
 vm_offset_t
-acpi_rsdp()
+acpi_rsdp(void)
 {
 	return (rsdp);
 }
 
 bool
-has_acpi()
+has_acpi(void)
 {
 	return rsdp != 0;
 }