cmd: efidebug: fix -Werror=type-limits warning

Compiling with -Wtype-limits yields:

cmd/efidebug.c:968:32: error: comparison is always false due to limited
range of data type [-Werror=type-limits]
  968 |  if (*endp != '\0' || bootnext > 0xffff) {
      |

Remove the superfluous check.

Fixes: 59df7e7e77e7 ("cmd: add efidebug command")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/cmd/efidebug.c b/cmd/efidebug.c
index 668e5c4..5cc0a41 100644
--- a/cmd/efidebug.c
+++ b/cmd/efidebug.c
@@ -970,7 +970,7 @@
 		return CMD_RET_USAGE;
 
 	bootnext = (u16)simple_strtoul(argv[1], &endp, 16);
-	if (*endp != '\0' || bootnext > 0xffff) {
+	if (*endp) {
 		printf("invalid value: %s\n", argv[1]);
 		r = CMD_RET_FAILURE;
 		goto out;