Remove one line comment

This patch is going to remove a line comment, which was added in this
commit,

commit 55fea07
Author: Jim Kingdon <jkingdon@engr.sgi.com>
Date:   Tue Sep 14 01:08:22 1993 +0000

        * remote.c: Define remote_debug to 0 and #if 0 baud_rate.  Temporary
        hack so this file compiles again.

        * remote-utils.c (gr_multi_scan): Cast return value from alloca.
        (gr_multi_scan): #if 0 never-reached return(-1).

and at that moment, remote_prepare_to_store does updates some global
state,

static void
remote_prepare_to_store ()
{
  /* Make sure the entire registers array is valid.  */
  read_register_bytes (0, (char *)NULL, REGISTER_BYTES);
}

However, now, remote_prepare_to_store doesn't do that at all, and
rsa->sizeof_g_packet is updated in init_remote_state, so the line of
comment is out of date, and this patch removes it.

gdb:

2017-07-18  Yao Qi  <yao.qi@linaro.org>

	* remote.c (store_registers_using_G): Remove one line comment.

gdb/ChangeLog

@@ -1,3 +1,7 @@
+2017-07-18  Yao Qi  <yao.qi@linaro.org>
+
+	* remote.c (store_registers_using_G): Remove one line comment.
+
 2017-07-18  Yao Qi  <yao.qi@linaro.org>
 
 	* regcache.c (regcache_cpy): Simplify it.

gdb/remote.c

@@ -7844,8 +7844,6 @@ store_registers_using_G (const struct regcache *regcache)
      each byte encoded as two hex characters.  */
   p = rs->buf;
   *p++ = 'G';
-  /* remote_prepare_to_store insures that rsa->sizeof_g_packet gets
-     updated.  */
   bin2hex (regs, p, rsa->sizeof_g_packet);
   putpkt (rs->buf);
   getpkt (&rs->buf, &rs->buf_size, 0);