twinkie: bug fix for injector.c:cmd_bufrd
twinkie: bug fix for injector.c:cmd_bufrd

bug: when typing
> tw bufrd 3 2
in twinkie console, the command will output 3 elements
However, the third argument(3) is where it starts output
the elements; and the fourth argument(2) is the number
of elements to be printed.

Original code uses: "cnt = strtoi(argv[0], &e, 10);" to
get the count.
It should use "cnt = strtoi(argv[1], &e, 10);" instead.

Signed-off-by: Dawei Li <38abe79b34fa2595bbef2a599b70892542e08f8c@google.com>

Change-Id: I04cf041e47cdf72c5189e4b8446c8f8e4cc5e2e5
Reviewed-on: https://chromium-review.googlesource.com/293561
Tested-by: Dawei Li <38abe79b34fa2595bbef2a599b70892542e08f8c@google.com>
Reviewed-by: Sheng-liang Song <20a24593f82e573953076a0eeaf8f3cfb817a534@chromium.org>
Commit-Queue: Sheng-liang Song <20a24593f82e573953076a0eeaf8f3cfb817a534@chromium.org>

coreboot/chrome-ec,akappy7/ChromeOS_EC_LED_Diagnostics,coreboot/chrome-ec,coreboot/chrome-ec,akappy7/ChromeOS_EC_LED_Diagnostics,akappy7/ChromeOS_EC_LED_Diagnostics,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,akappy7/ChromeOS_EC_LED_Diagnostics,akappy7/ChromeOS_EC_LED_Diagnostics