Fix stack smashing detected issue

Fix stack smashing detected issue

le_conn_param data should be filled as a uint16 not uint32.
it can cause stack overflow.

 #3  0xf7233a70 in __GI___fortify_fail_abort (need_backtrace=
     need_backtrace@entry=false, msg=0xf72741cc "stack smashing detected")
     at fortify_fail.c:28
 No locals.
 #4  0xf7233a34 in __stack_chk_fail () at stack_chk_fail.c:29
 No locals.
 #5  0x00958f88 in update_le_conn_parm (conn=<optimized out>, msg=0x0,
     user_data=<optimized out>) at src/device.c:4216
         device = <optimized out>
         io = <optimized out>
         fd = <optimized out>
         param = {min = 72, max = 72, latency = 0, to_multiplier = 200}
         __func__ = "update_le_conn_parm"

Change-Id: Ia0df33fc30e31057ef4b2a07a0ac64d61d67dd81