x86: fix up system call numbering nit

As pointed out by Jiri Slaby: when I resolved the the 32-bit x85 system
call entry tables for prlimit (due to the conflict with fanotify), I
forgot to add the numbering in comments that we do for every fifth entry.

Reported-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/x86/ia32/ia32entry.S

@@ -844,5 +844,5 @@ ia32_sys_call_table:
 	.quad compat_sys_recvmmsg
 	.quad sys_fanotify_init
 	.quad sys32_fanotify_mark
-	.quad sys_prlimit64
+	.quad sys_prlimit64		/* 340 */
 ia32_syscall_end: