examples/nvme/identify: exit after showing help text

Exit after showing the help text.

If the user specifies -H, it is confusing that
the regular execution of the program continues,
which might mislead the user to think that the
option they specified is not taking effect.

Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Change-Id: I52d8e0f6c720c7ce1d66bddb99181babb12cef1f
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/5895
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Mellanox Build Bot
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>

examples/nvme/identify/identify.c

@@ -2001,7 +2001,7 @@ parse_args(int argc, char **argv)
 			break;
 		case 'H':
 			usage(argv[0]);
-			break;
+			exit(EXIT_SUCCESS);
 		case 'V':
 			g_vmd = true;
 			break;