Fix accessing wrong index

Fix accessing wrong index

0  rawmemchr () at ../sysdeps/arm/armv6/rawmemchr.S:28
1  0xb6ac6108 in _IO_str_init_static_internal (sf=sf@entry=0xb31fecf0, ptr=ptr@entry=0xb2800050 <error: Cannot access memory at address 0xb2800050>, size=size@entry=0, pstart=pstart@entry=0x0) at strops.c:41
2  0xb6ab8644 in _IO_vsscanf (string=0xb2800050 <error: Cannot access memory at address 0xb2800050>, format=0xb6ffafec "%d:%d:%d", format@entry=0xbeeb69d8 "", args=..., args@entry=...) at iovsscanf.c:40
3  0xb6ab20f4 in __sscanf (s=<optimized out>, format=0xb6ffafec "%d:%d:%d") at sscanf.c:32
4  0xb6fea652 in sync_windowsize (fd=<optimized out>, cookie=<optimized out>) at /usr/src/debug/sdbd-3.0.48/src/services.c:1309
5  0xb6fe9f04 in service_bootstrap_func (x=0xb8bae490) at /usr/src/debug/sdbd-3.0.48/src/services.c:66
6  0xb6b9af04 in start_thread (arg=0xb31ff410) at pthread_create.c:335
7  0xb6b297d8 in ?? () at ../sysdeps/unix/sysv/linux/arm/clone.S:86 from /lib/libc.so.6

Change-Id: I654a7d28464ea6f4173ef0af4b468f2429067d21