vmci_host: print unexpanded names of ioctl requests in debug messages

__stringify macro function expands its arguments, but in this messages
we expect to see ioctl request name instead of it's _IOC macro
expansion.

$ cat stringify.c

#include <stdio.h>
#include <asm/ioctl.h>

#define __stringify_1(x)	#x
#define __stringify(x)		__stringify_1(x)

#define VMCI_DO_IOCTL(ioctl_name) \
    char *name = __stringify(IOCTL_VMCI_ ## ioctl_name);

int main() {
        VMCI_DO_IOCTL(INIT_CONTEXT)
        printf("%s\n", name);
}
$ cc stringify.c
$ ./a.out
(((0U) << (((0+8)+8)+14)) | (((7)) << (0+8)) | (((0xa0)) << 0) | ((0) << ((0+8)+8)))

Signed-off-by: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
Link: https://lore.kernel.org/r/20210302153346.300416-1-glebfm@altlinux.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>